86 results on '"Bouillon, Roger"'
Search Results
2. The diagnosis and treatment of male osteoporosis: Defining, assessing, and preventing skeletal fragility in men
- Author
-
Boonen, Steven, Kaufman, Jean-Marc, Goemaere, Stefan, Bouillon, Roger, and Vanderschueren, Dirk
- Published
- 2007
- Full Text
- View/download PDF
3. Dermal fibroblasts pretreated with a sterol Δ 7-reductase inhibitor produce 25-hydroxyvitamin D 3 upon UVB irradiation
- Author
-
Vantieghem, Katleen, De Haes, Petra, Bouillon, Roger, and Segaert, Siegfried
- Published
- 2006
- Full Text
- View/download PDF
4. 1,25-Dihydroxyvitamin D 3 and analogues protect primary human keratinocytes against UVB-induced DNA damage
- Author
-
De Haes, Petra, Garmyn, Marjan, Verstuyf, Annemieke, De Clercq, Pierre, Vandewalle, Maurits, Degreef, Hugo, Vantieghem, Katleen, Bouillon, Roger, and Segaert, Siegfried
- Published
- 2005
- Full Text
- View/download PDF
5. C-peptide, insulin-like growth factors I and II, and insulin-like growth factor binding protein-1 in umbilical cord serum: correlations with birth weight
- Author
-
Verhaeghe, Johan, Bree, Rita Van, Herck, Erik Van, Laureys, Jozef, Bouillon, Roger, and Assche, Andre Van
- Subjects
Insulin-like growth factors -- Physiological aspects ,Birth weight -- Physiological aspects ,Health - Abstract
Insulin-like growth factor (IGF) I level influences birth weight. Insulin-like growth factor II and insulin are also related to fetal growth. Blood samples taken during the third trimester of pregnancy from the umbilical cords of 538 infants were analyzed and compared with the infants' birth weights. Concentrations of IGF-I increased in average-birth-weight (AGA) infants until the 39th week of pregnancy. After that, there was a 21% decrease until 41 weeks. Small-for-gestational-age (SGA) infants had levels of IGF-I that were 40% lower on average than AGA or large for gestational age (LGA) infants. IGF-II was 10% higher in LGA infants than in SGA infants and 8% higher than in AGA infants. However, SGA and AGA infants had similar levels of IGF-II. Higher levels of insulin-like growth factor binding protein-1 were found in newborns with evidence of growth retardation.
- Published
- 1993
6. Meeting report from the 3rd IFMRS/KU Leuven Herbert Fleisch Workshop, Brugge, Belgium, 17–19 March 2019.
- Author
-
Maes, Christa, Bouillon, Roger, and Martin, T. John
- Subjects
- *
OSTEOCLASTS , *ALENDRONATE , *BONE spurs , *TRANSFORMING growth factors-beta , *MESENCHYMAL stem cells , *BONE marrow cells , *BONE density - Published
- 2019
- Full Text
- View/download PDF
7. Vitamin D insufficiency: Definition, diagnosis and management.
- Author
-
Bouillon, Roger and Carmeliet, Geert
- Abstract
Severe vitamin D deficiency can be defined as the dose of vitamin D or serum 25OHD concentrations needed to prevent nutritional rickets or osteomalacia. There is large international consensus that these diseases can be prevented by 400 IU of vitamin D/d and 25OHD above 30 nmol/l (12 ng/ml). Vitamin D deficiency can also accelerate the risk of fractures and probably also of falls in elderly subjects but there is no consensus on the required daily doses or minimal 25OHD threshold for these endpoints. The majority of experts consider 800 IU/d and serum 25OHD above 50 nmol/l (20 ng/ml) as sufficient, with a minority opinion aiming for 75 nmol/l or even higher. For other extra-skeletal endpoints, no hard evidence is available to define whether or not this is causally related to vitamin D status. Therefore, for these endpoints no minimal dosage or 25OHD threshold can be defined. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
8. Seasonality of birth in patients with type 1 diabetes
- Author
-
Bouillon, Roger, Decallonne, Brigitte, Gysemans, Conny, Etten, Evelyne van, Mathieu, Chantal, Virtanen, Suvi, Jarvelin, Marjo-Riitta, Hypponen, Elina, Weizman, Abraham, Gurwitz, David, Roep, Bart O, Giphart, Marius J, Eerligh, Peter, Valdigem, Gustavo, Koeleman, Bobby P C, Tuomilehto, J, Muntoni, S, Karvonen, M, and Muntoni, Sa
- Subjects
Type 1 diabetes -- Risk factors ,Vitamin D deficiency -- Health aspects ,Seasons -- Health aspects ,Childbirth -- Environmental aspects ,Infants -- Health aspects - Published
- 2002
9. Vitamin D metabolites in captivity? Should we measure free or total 25(OH)D to assess vitamin D status?
- Author
-
Bikle, Daniel, Bouillon, Roger, Thadhani, Ravi, and Schoenmakers, Inez
- Subjects
- *
VITAMIN D metabolism , *VITAMIN D-binding proteins , *KERATINOCYTES , *BIOMARKERS , *ALBUMINS , *THERAPEUTICS - Abstract
There is general consensus that serum 25(OH)D is the best biochemical marker for nutritional vitamin D status. Whether free 25(OH)D would be a better marker than total 25(OH)D is so far unclear. Free 25(OH)D can either be calculated based on the measurement of the serum concentrations of total 25(OH)D, vitamin D-binding protein (DBP), albumin, and the affinity between 25(OH)D and its binding proteins in physiological situations. Free 25(OH)D can also be measured directly by equilibrium dialysis, ultrafitration or immunoassays. During the vitamin D workshop held in Boston in March 2016, a debate was organized about the measurements and clinical value of free 25(OH)D, and this debate is summarized in the present manuscript. Overall there is consensus that most cells apart from the renal tubular cells are exposed to free rather than to total 25(OH)D. Therefore free 25(OH)D may be highly relevant for the local production and action of 1,25(OH) 2 D. During the debate it became clear that there is a need for standardization of measurements of serum DBP and of direct measurements of free 25(OH)D. There seems to be very limited genetic or racial differences in DBP concentrations or (probably) in the affinity of DBP for its major ligands. Therefore, free 25(OH)D is strongly correlated to total 25(OH)D in most normal populations. Appropriate studies are needed to define the clinical implications of free rather than total 25(OH)D in normal subjects and in disease states. Special attention is needed for such studies in cases of abnormal DBP concentrations or when one could expect changes in its affinity for its ligands. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
10. Comparison of calcifediol with vitamin D for prevention or cure of vitamin D deficiency.
- Author
-
Bouillon, Roger and Quesada Gomez, Jose Manuel
- Subjects
- *
VITAMIN D deficiency , *CALCIFEDIOL , *CHYLOMICRONS , *VITAMIN D receptors , *DIETARY supplements , *VITAMIN D , *INTESTINAL absorption , *PORTAL vein - Abstract
Vitamin D deficiency remains prevalent, with about 7% of the world's population living with severe vitamin D deficiency and about one third with mild deficiency. We compare the relative merits of calcifediol or 25-hydroxyvitamin D (25OHD) compared to vitamin D itself for supplementation as to prevent or cure vitamin D deficiency. The intestinal absorption of calcifediol is nearly 100% and thus higher than that of vitamin D itself. Moreover, calcifediol is absorbed by the intestinal cells and transported through the portal vein and thus immediately accessible to the circulation, while vitamin D is transported with chylomicrons through the lymph system. Therefore, in case of fat malabsorption or after bariatric surgery, calcifediol is much better absorbed in comparison with vitamin D itself. Serum 25OHD increases linearly with increasing doses of calcifediol, whereas serum 25OHD reaches a plateau when higher oral doses of vitamin D are used. Calcifediol, on a weight basis, is about 3 times more potent than vitamin D in subjects with mild vitamin D deficiency. This potency is even 6–8 times higher than vitamin D when baseline serum 25OHD is higher or when large doses are compared. In conclusion, calcifediol is an alternative option to correct vitamin D deficiency and may even be the preferred strategy in case of intestinal fat malabsorption, after bariatric surgery or in case of other conditions with suspected impaired 25-hydroxylase activity in the liver. • Vitamin D deficiency is highly prevalent worldwide. • Adequate strategies to correct this deficiency are needed. • Vitamin D supplementation is the most widely applied strategy to correct vitamin D deficiency. • Calcifediol or 25-hydroxyvitamin D is an alternative strategy to correct vitamin D deficiency. • The intestinal absorption of calcifediol is better than that of vitamin D, especially in case of intestinal malabsorption or bariatric surgery. • Calcifediol is several-fold more potent (on a weight basis) than vitamin D. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
11. Nutritional rickets: calcium or vitamin D deficiency?
- Author
-
Bouillon, Roger
- Subjects
VITAMIN D metabolism ,CHILD nutrition ,RICKETS ,SERIAL publications ,INGESTION ,CALCIUM compounds ,VITAMIN D ,DIETARY supplements ,CALCIUM ,VITAMIN D deficiency ,DISEASE risk factors ,DISEASE complications - Abstract
The author reflects on a study on the interaction between vitamin D status and calcium intake in Nigerian children with rickets, as well as its diagnostic and therapeutic implications. Topics include the history of rickets in Low Countries like The Netherlands and England in the mid-17th century and the diagnostic tools in rickets diagnosis like radiology.
- Published
- 2021
- Full Text
- View/download PDF
12. Vitamin D signaling in calcium and bone homeostasis: A delicate balance.
- Author
-
Carmeliet, Geert, Dermauw, Veronique, and Bouillon, Roger
- Abstract
Loss-of-function mutations in genes involved in the vitamin D/vitamin D receptor system have clearly evidenced its critical role for mineral and skeletal homeostasis. Adequate levels of 1,25-dihydroxyvitamin D [1,25(OH) 2 D], the active form of vitamin D are therefore required and depend on sufficient sunlight exposure or dietary intake. Intestinal calcium absorption is a primary target of 1,25(OH) 2 D action and this pathway indirectly promotes calcium incorporation in bone. Severe vitamin D deficiency may thus decrease bone quality and leads to osteomalacia, whereas less severe deficiency increases the risk of osteoporosis and bone fractures. On the other hand, high vitamin D levels together with low dietary calcium intake will increase bone resorption and decrease bone mineralization in order to maintain normal serum calcium levels. Appropriate dietary calcium intake and sufficient serum vitamin D levels are thus important for skeletal health. Dosing of calcium and vitamin D supplements is still debated and requires further investigation. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
13. Why modest but widespread improvement of the vitamin D status is the best strategy?
- Author
-
Bouillon, Roger
- Subjects
VITAMIN D in the body ,CALCIUM metabolism ,PROTEIN precursors ,DIETARY supplements ,BONE density ,BONE fractures ,PARATHYROID hormone ,TRANSCRIPTION factors - Abstract
Vitamin D is a precursor for a secosteroid ligand of a major transcription factor, VDR, and is vital for normal bone mineralization. It also regulates many other genes so that it may be involved in many extra skeletal health effects. The optimal vitamin D status is controversial but there is a wide unanimity that the vitamin D status can and should be improved for some risk groups. To normalize serum calcium homeostasis as based on normal levels of serum 1,25(OH)
2 D3 or parathyroid hormone, or to optimize intestinal calcium absorption or bone mineral density in adults or elderly subjects, serum 25OHD should be 20 ng/ml or higher. A daily vitamin D supplement of at least 400 IU or preferably 800 IU of vitamin D3 can reduce the risk of fractures and probably also falls in elderly subjects, especially when combined with an optimal calcium intake. There is no formal proof of causality to define an optimal vitamin D intake or serum 25OHD based on its presumed extra skeletal health effects but the guidelines for bone health would probably eliminate also most negative extra skeletal health effects. The recommended vitamin D3 supplement of 400–800 IU/d for adults also corresponds to the daily replacement dose calculated from metabolic clearance studies. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
14. TRPV4-Mediated Calcium Influx Regulates Terminal Differentiation of Osteoclasts.
- Author
-
Masuyama, Ritsuko, Vriens, Joris, Voets, Thomas, Karashima, Yuji, Owsianik, Grzegorz, Vennekens, Rudi, Lieben, Liesbet, Torrekens, Sophie, Moermans, Karen, Vanden Bosch, An, Bouillon, Roger, Nilius, Bernd, and Carmeliet, Geert
- Subjects
FLUIDS ,OSTEOCLASTS ,BONE cells ,OSTEOCLAST inhibition - Abstract
Summary: Calcium signaling controls multiple cellular functions and is regulated by the release from internal stores and entry from extracellular fluid. In bone, osteoclast differentiation is induced by RANKL (receptor activator of NF-κB ligand)-evoked intracellular Ca
2+ oscillations, which trigger nuclear factor-activated T cells (NFAT) c1-responsive gene transcription. However, the Ca2+ channels involved remain largely unidentified. Here we show that genetic ablation in mice of Trpv4, a Ca2+ -permeable channel of the transient receptor potential (TRP) family, increases bone mass by impairing bone resorption. TRPV4 mediates basolateral Ca2+ influx specifically in large osteoclasts when Ca2+ oscillations decline. TRPV4-mediated Ca2+ influx hereby secures intracellular Ca2+ concentrations, ensures NFATc1-regulated gene transcription, and regulates the terminal differentiation and activity of osteoclasts. In conclusion, our data indicate that Ca2+ oscillations and TRPV4-mediated Ca2+ influx are sequentially required to sustain NFATc1-dependent gene expression throughout osteoclast differentiation, and we propose TRPV4 as a therapeutic target for bone diseases. [Copyright &y& Elsevier]- Published
- 2008
- Full Text
- View/download PDF
15. Hypogonadism in male outpatients with sarcoidosis.
- Author
-
Spruit, Martijn A., Thomeer, Michiel J., Gosselink, Rik, Wuyts, Wim A., Van Herck, Erik, Bouillon, Roger, Demedts, Maurits G., and Decramer, Marc
- Abstract
Summary: Hypogonadism is assumed to be present in sarcoidosis. Nevertheless, a comparison of circulating sex hormone concentrations of male sarcoidosis patients with those of healthy men has never been done. Moreover, it remains unknown if hypogonadism may contribute to a reduced muscle function, exercise intolerance, diminished vitality and depressed mood in male sarcoidosis patients. Pulmonary function, muscle function, exercise tolerance, vitality, mood, circulating sex hormone concentrations and C-reactive protein were assessed in 30 male sarcoidosis patients and 26 age-matched men with a normal pulmonary function. On average, patients had a restrictive pulmonary function, worse inspiratory and quadriceps muscle function, functional exercise intolerance, diminished vitality, depressed mood and increased systemic inflammation. Moreover, patients had significantly lower circulating (free) testosterone concentrations, while circulating sex hormone-binding globulin tended to be lower (p=0.0515). Circulating gonadotrophin concentrations were comparable. Non-significant relationships were found between sex hormones, clinical outcomes and C-reactive protein in patients with sarcoidosis. A significant number of male outpatients with sarcoidosis (46.7%) had low circulating testosterone concentrations, which was most probably caused by hypogonadotrophism. The clinical relevance of hypogonadism in male outpatients with sarcoidosis, however, remains currently unknown. Indeed, poor inspiratory and quadriceps muscle function, exercise intolerance, diminished vitality and depressed mood were not related to hypogonadism in these patients. [Copyright &y& Elsevier]
- Published
- 2007
- Full Text
- View/download PDF
16. Vitamin D and cancer
- Author
-
Bouillon, Roger, Eelen, Guy, Verlinden, Lieve, Mathieu, Chantal, Carmeliet, Geert, and Verstuyf, Annemieke
- Subjects
- *
VITAMIN D , *STEROID hormones , *CANCER , *KERATINOCYTES - Abstract
Abstract: 1,25-dihydroxy Vitamin D [1,25-(OH)2D] exerts its effects via the vitamin D receptor (VDR) that belongs to the steroid/thyroid hormone receptor superfamily leading to gene regulation which results in various biological responses. Within the last two decades, the receptor has been shown to be present not only in classical target tissues such as bone, kidney and intestine but also in many other non-classical tissues. Besides the almost universal presence of VDRs, some cell types (e.g. keratinocytes, monocytes, bone, placenta) are capable of metabolizing 25-hydroxyvitamin D to 1,25(OH)2D by the enzyme 1α-hydroxylase (CYP27B1). The combined presence of 25(OH)D-1α-hydroxylase as well as the specific receptor in several tissues introduced the idea of a paracrine role for 1,25(OH)2D. Moreover, it has been demonstrated that 1,25(OH)2D can induce differentiation and inhibit proliferation of a wide variety of cell types. The molecular mechanisms behind this antiproliferative action is thoroughly explored but the whole picture is still difficult to understand. Important cell cycle regulators are involved such as cyclins, cyclin dependent kinases and their corresponding inhibitors as well as E2F transcription factors and accompanying pocket proteins. However the precise hierarchical structure of this wide diversity of actions of 1,25(OH)2D on genes influencing cell cycle progression is not firmly established nor do we understand which pathways are essential and which redundant. The antiproliferative action makes 1,25-(OH)2D and its analogs a possible therapeutic tool to treat hyperproliferative disorders, among which different types of cancer. This review focuses on the effects of 1,25(OH)2D and its analogs on cell proliferation, the results in in vivo experiments in Vitamin D deficient or resistant animals to cancer and the current epidemiological and intervention studies linking Vitamin D status or treatment and human cancer. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
17. Vitamin D resistance.
- Author
-
Bouillon, Roger, Verstuyf, Annemieke, Mathieu, Chantal, Van Cromphaut, Sophie, Masuyama, Ritsuko, Dehaes, Petra, and Carmeliet, Geert
- Subjects
VITAMIN D ,ULTRAVIOLET radiation ,HYDROXYLATION ,TRANSCRIPTION factors ,CARDIAC hypertrophy ,IMMUNE system ,HOMEOSTASIS - Abstract
Vitamin D is a secosteroid of nutritional origin but can also be generated in the skin by ultraviolet light. After two hydroxylations 1,25-(OH)
2 vitamin D avidly binds and activates the vitamin D receptor (VDR), a nuclear transcription factor, hereby regulating a large number of genes. The generation of VDR deficient mice has expanded the knowledge on vitamin D from a calcium-regulating hormone to a humoral factor with extensive actions. The effects of the vitamin D system on calcium and bone homeostasis are largely mediated by promoting active intestinal calcium transport via the induction of the epithelial calcium channel TRPV6. Although VDR is redundant in bone, it may regulate the differentiation and function of several bone cells. In skin, VDR expression in keratinocytes is essential in a ligand-independent manner for the maintenance of the normal hair cycle. Therefore, VDR but not vitamin D deficiency results in alopecia. Moreover, 1,25-(OH)2 vitamin D impairs the proliferation not only of keratinocytes but also of many cell types by regulating the expression of cell cycle genes, leading to a G1 cell cycle arrest. In addition, VDR inactivation in mice results in high renin hypertension, cardiac hypertrophy and thrombogenesis. Finally, a dual effect of vitamin D was observed in the immune system where it stimulates the innate immune system while tapering down excessive activation of the acquired immune system. Taken together, the vitamin D endocrine system not only regulates calcium homeostasis but affects several systems mainly by altering gene expression but also by ligand-independent actions. [Copyright &y& Elsevier]- Published
- 2006
- Full Text
- View/download PDF
18. Mechanisms for the selective action of Vitamin D analogs
- Author
-
Bouillon, Roger, Verlinden, Lieve, Eelen, Guy, De Clercq, Pierre, Vandewalle, Maurits, Mathieu, Chantal, and Verstuyf, Annemieke
- Subjects
- *
STEROID hormones , *VITAMIN D , *IMMUNOLOGIC diseases , *CELL proliferation - Abstract
Abstract: The non-classical effects of 1,25(OH)2D3 create possible therapeutic applications for immune modulation (e.g. auto-immune diseases and graft rejection), inhibition of cell proliferation (e.g. psoriasis, cancer) and induction of cell differentiation (e.g. cancer). The major drawback related to the use of 1,25(OH)2D3 is its calcemic effect, which prevents the application of pharmacological concentrations. Several analogs are now available that show modest to good selectivity with regard to specific effects (e.g. anticancer or immune effects or bone anabolism versus hypercalcemia) when tested in appropriate in vivo models. The molecular basis for this selectivity is only partially understood and probably a variable mixture of mechanisms. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
19. Vitamin D status in the elderly: seasonal substrate deficiency causes 1,25-dihydroxycholecalciferol deficiency.
- Author
-
Bouillon, Roger A., Auwerx, Johan H., Lissens, Willy D., and Pelemans, Walter K.
- Subjects
VITAMIN D ,DIHYDROXYCHOLECALCIFEROLS ,HYDROXYCHOLECALCIFEROLS ,ERGOCALCIFEROL ,STEROID hormones - Abstract
The seasonal variation of 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol was analyzed in 240 elderly subjects (mean age: 78 yr) in Belgium. Serum 25-hydroxychole- calciferol was lowest from February untilMay (mean levels <25 nmol/L). Summer peak levels were, however, not higher than nadir levels in younger control subjects. A seasonal variation in total and free 1,25-dihydroxycholecalciferol concentrations was also observed in the geriatric population with a nadir in February and March (50 ± 24 pmol/L). The peak values in summer (110 ± 33 pmol/L) were not different from those of the younger controls. Serum calcium and phosphate were decreased whereas alkaline phosphatase and parathyroid hormone were increased throughout the year in the geriatric patients. Oral 25-hydroxycholecalciferol treatment rapidly normalized serum 1,25-dihydroxycholecalciferol concentrations in vitamin 1)-deficient subjects. Deficiency of both the vitamin D substrate and hormone is frequent in the elderly population in Belgium. [ABSTRACT FROM AUTHOR]
- Published
- 1987
- Full Text
- View/download PDF
20. Reduction of blood pressure with oral magnesium supplementation in women with mild to moderate hypertension.
- Author
-
Witteman, Jacqueline C. M., Grobbee, Diederick E., Derkx, Frans H. M., Bouillon, Roger, de Bruijn, Anthony M., and Hofinan, Albert
- Subjects
HYPERTENSION ,THERAPEUTICS ,MAGNESIUM in the body ,HEALTH of older women ,FOOD consumption ,BLOOD lipoproteins - Abstract
In a double-blind controlled trial, 91 middle-aged and elderly women with mild to moderate hypertension who were not on antihypertensive medication were randomly assigned to treatment with magnesium aspartate-HCl (20 mmol Mg/d) or placebo for 6 mo. Magnesium aspartate-HCl in the given dose was well-tolerated and was not associated with an increased frequency of diarrhea compared with placebo. At the end of the study, systolic blood pressure had fallen by 2.7 mm Hg (95% CI -1.2, 6.7; P = 0.18) and diastolic blood pressure by 3.4 mm Hg (1.3, 5.6; P = 0.003) more in the magnesium group than in the placebo group. Blood pressure response was not associated with baseline magnesium status, as measured by dietary magnesium intake and urinary magnesium excretion. Urinary magnesium excretion in the magnesium group increased by 50% during the intervention period. No changes were seen in other biochemical indexes, including serum concentrations of total and high-density-lipoprotein cholesterol. The findings suggest that oral supplementation with magnesium aspartate-HCl may lower blood pressure in subjects with mild to moderate hypertension. [ABSTRACT FROM AUTHOR]
- Published
- 1994
- Full Text
- View/download PDF
21. 14th Vitamin D Workshop consensus on vitamin D nutritional guidelines
- Author
-
Henry, Helen L., Bouillon, Roger, Norman, Anthony W., Gallagher, J. Christopher, Lips, Paul, Heaney, Robert P., Vieth, Reinhold, Pettifor, John M., Dawson-Hughes, Bess, Lamberg-Allardt, Christel J., and Ebeling, Peter R.
- Published
- 2010
- Full Text
- View/download PDF
22. Fourteenth Workshop on Vitamin D
- Author
-
Norman, Anthony W., Bouillon, Roger, and Adamski, Jerzy
- Published
- 2010
- Full Text
- View/download PDF
23. In memoriam: AW Norman, the founding father of the vitamin D workshops.
- Author
-
Bouillon, Roger
- Subjects
- *
FATHERS , *CHOLECALCIFEROL , *VITAMINS , *VITAMIN D - Abstract
• Anthony W. Norman. • Vitamin D. • Vitamin D workshop. • In memoriam. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
24. Nutritional rickets: Historic overview and plan for worldwide eradication.
- Author
-
Bouillon, Roger and Antonio, Leen
- Subjects
- *
RICKETS , *VITAMIN D deficiency , *ETIOLOGY of diseases , *HUMAN skin color , *VITAMIN D , *IODINE deficiency , *CHILD nutrition , *ENDOCRINE system - Abstract
• Rickets is the tip of an iceberg of vitamin D deficiency disorders. • Nutritional rickets can be due to vitamin D and or calcium deficiency. • Rickets has been largely eradicated in countries with a systematic vitamin Dsupplementation of all infants. • Rickets is still endemic in many countries or risk groups. • A strategy is needed to implement a strategy to eradicate nutritional rickets. • This is similar to the WHO eradication project for iodine deficiency disorders.. Rickets was first described in great detail in the mid 17th century and was affecting a great number of children in major European cities. The disease, however, existed already in the Roman times. The etiology of this disease remained enigmatic until the 1920s when two different mechanisms, lack of exposure to sunlight and lack of a dietary factor were finally solved by the discovery of vitamin D and its dual origin. Soon thereafter, the implementation of vitamin D supplementation for all infants and small children largely eliminated nutritional rickets in Europe and North America. It took nearly a century to elucidate the complex chemistry, metabolism, mode and spectrum of activity of the vitamin D endocrine system. Nutritional rickets, whether due to simple vitamin D or calcium deficiency or both, remains widely ravaging many infants and children around the world. Asian countries and the Middle East are mainly confronted with vitamin D deficiency whereas many African and some Asian countries face calcium deficiency rickets. Immigrants and refugees or in general people with a darker skin living in moderate climate zone are also confronted with this disease. There is great consensus how this disease could be prevented or cured. In collaboration with most international professional societies, we prepare a memorandum, in line with the successful battle against iodine deficiency disorders, to convince the World Health Organization and its member states to start an implementation program to eradicate nutritional rickets by 2030. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
25. NIH deltanoids meeting on Vitamin D and cancer: Conclusion and strategic options
- Author
-
Bouillon, Roger, Moody, Terry, Sporn, Michael, Barrett, J. Carl, and Norman, Anthony W.
- Subjects
- *
CANCER treatment , *STEROID hormones , *FAT-soluble vitamins , *VITAMIN D deficiency - Abstract
Abstract: A meeting on “Cancer Chemoprevention and Cancer Treatment; role of vitamin D, 1α,25-(OH)2D3 and deltanoids” was held on the NIH Congres, Bethesda in November 2004. The following conclusions were presented at the end of this symposium. Vitamin D deficiency and insufficiency are worldwide problems and are associated with several health problems including higher cancer prevalence. There is convincing evidence that the active vitamin D hormone, 1α,25(OH)2D3, can decrease cell proliferation, modify cell apoptosis and control malignant cell growth. Therefore academia, public funding agencies and industry should urgently design appropriate studies to better define the causal relationship between vitamin D nutrition and cancer, define the optimal vitamin D nutrition based on accurate 25(OH)D measurement and inform the public and medical profession accordingly. Selective vitamin D receptor modulators are a potentially interesting new class of chemopreventive and chemotherapeutic agents as demonstrated by several first generation analogs have provided a convincing proof of concept. In the mean time, the public should be informed about the risks of vitamin D deficiency and insufficiency and appropriate steps should be taken to improve the vitamin D nutritional status of large parts of the world population. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
26. The Author Replies:.
- Author
-
Bouillon, Roger
- Subjects
- *
LETTERS to the editor , *KIDNEY diseases - Abstract
A letter to the editor and a reply is presented in response to the article about Fetuin-A as one of the several potential vascular calcification inhibitors in chronic kidney disease (CKD) patients in the 2010 issue.
- Published
- 2010
- Full Text
- View/download PDF
27. 13th Workshop consensus for vitamin D nutritional guidelines
- Author
-
Norman, Anthony W., Bouillon, Roger, Whiting, Susan J., Vieth, Reinhold, and Lips, Paul
- Published
- 2007
- Full Text
- View/download PDF
28. Preface.
- Author
-
Bouillon, Roger
- Published
- 2011
- Full Text
- View/download PDF
29. Vitamin D: Basic and clinical research in vitamin D, vitamin D analogs and bone health
- Author
-
Bouillon, Roger
- Published
- 2010
- Full Text
- View/download PDF
30. Vitamin D is a multifunctional hormone
- Author
-
Bouillon, Roger
- Published
- 2010
- Full Text
- View/download PDF
31. OC12. Specific inhibition of the VEGF homolog placental growth factor is protective against osteolytic bone metastasis in mice.
- Author
-
Coenegrachts, Lieve, Maes, Christa, Torrekens, Sophie, Van Looveren, Riet, Mazzone, Massimiliano, Guise, Theresa A., Bouillon, Roger, Carmeliet, Peter, and Carmeliet, Geert
- Published
- 2008
- Full Text
- View/download PDF
32. Introduction
- Author
-
Bouillon, Roger
- Published
- 2007
- Full Text
- View/download PDF
33. Seasonality of birth in patients with type 1 diabetes.
- Author
-
Mathieu, Chantal, van Etten, Evelyne, Gysemans, Conny, Decallonne, Brigitte, and Bouillon, Roger
- Published
- 2002
- Full Text
- View/download PDF
34. Synergism between sirolimus and 1,25-dihydroxyvitamin D 3 in vitro and in vivo
- Author
-
Branisteanu, Dumitru D, Mathieu, Chantal, and Bouillon, Roger
- Published
- 1997
- Full Text
- View/download PDF
35. Prevention of murine experimental allergic encephalomyelitis: cooperative effects of cyclosporine and 1 α, 25-(OH) 2D 3
- Author
-
Branisteanu, Dumitru D., Waer, Mark, Sobis, Halina, Marcelis, Suzanne, Vandeputte, Michel, and Bouillon, Roger
- Published
- 1995
- Full Text
- View/download PDF
36. Physiological functions of vitamin D: what we have learned from global and conditional VDR knockout mouse studies.
- Author
-
Suda, Tatsuo, Masuyama, Ritsuko, Bouillon, Roger, and Carmeliet, Geert
- Subjects
- *
VITAMIN D , *KNOCKOUT mice , *CALCIUM in the body , *INTESTINAL physiology , *BIOLOGICAL transport , *BONE physiology - Abstract
The physiological role of vitamin D depends on calcium supply and calcium balance. When the calcium balance is normal, the major target of vitamin D is intestine. Vitamin D stimulates mainly active intestinal calcium transport mechanism. During a negative calcium balance, bone effects of vitamin D become dominant. Thus, the role of vitamin D in maintaining normocalcemia appears to have priority over skeletal integrity in these situations. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
37. Vitamin D: a pleiotropic hormone.
- Author
-
Verstuyf, Annemieke, Carmeliet, Geert, Bouillon, Roger, and Mathieu, Chantal
- Subjects
- *
STEROID hormones , *IMMUNE system , *VITAMIN D , *LEUCOCYTES , *MACROPHAGES , *GENE expression , *BONE diseases - Abstract
The secosteroid hormone 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) is the natural ligand for the vitamin D receptor, a member of the nuclear receptor superfamily. Upon binding of the ligand, the vitamin D receptor heterodimerizes with the retinoid X receptor and binds to vitamin D response elements in the promoter region of target genes to induce/repress their expression. The target genes that have been identified so far are heterogeneous in nature and reflect the great spectrum of biological activities of 1,25(OH)2D3. Within the last two decades, the receptor has been shown to be present not only in classical target tissues such as bone, kidney, and intestine, but also in many other nonclassical tissues, for example, in the immune system (T and B cells, macrophages, and monocytes), in the reproductive system (uterus, testis, ovary, prostate, placenta, and mammary glands), in the endocrine system (pancreas, pituitary, thyroid, and adrenal cortex), in muscles (skeletal, smooth, and heart muscles), and in brain, skin, and liver. Besides the almost universal presence of vitamin D receptors, different cell types (for example, keratinocytes, monocytes, bone, placenta) are capable of metabolizing 25-hydroxyvitamin D3 to 1,25(OH)2D3 by the enzyme 25(OH)D3-1α-hydroxylase, encoded by CYP27B1. The combined presence of CYP27B1 and the specific receptor in several tissues introduced the idea of a paracrine/autocrine role for 1,25(OH)2D3. Moreover, it has been demonstrated that 1,25(OH)2D3 can induce differentiation and inhibit proliferation of normal and malignant cells. Moreover, vitamin D deficiency is associated with an increased risk for nearly all major human diseases such as cancer, autoimmune diseases, cardiovascular, and metabolic diseases. In addition to the treatment of bone disorders with 1,25(OH)2D3, these newly discovered functions open perspectives for the use of 1,25(OH)2D3 as an immune modulator (for example, for the treatment of autoimmune diseases or prevention of graft rejection), inhibitor of cell proliferation, and inducer of cell differentiation (cancer). [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
38. Dermal fibroblasts pretreated with a sterol Δ7-reductase inhibitor produce 25-hydroxyvitamin D3 upon UVB irradiation
- Author
-
Vantieghem, Katleen, De Haes, Petra, Bouillon, Roger, and Segaert, Siegfried
- Subjects
- *
FIBROBLASTS , *STEROID hormones , *IRRADIATION , *RADIATION - Abstract
Abstract: As dermis is a physiological site of vitamin D3 photoproduction, the photo-endocrine vitamin D3 system was studied in dermal fibroblasts. Dermal fibroblasts contain the vitamin D receptor and induce 1α,25-dihydroxyvitamin D3-24-hydroxylase [CYP24] mRNA upon stimulation with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. In addition, dermal fibroblasts contain mRNA of the vitamin D3-25-hydroxylases (CYP2R1 and CYP27A1). However, we could not detect any 25-hydroxyvitamin D3 [25OHD3]-1α-hydroxylase mRNA in dermal fibroblasts and no CYP24 mRNA was induced upon ultraviolet [UVB] irradiation, even when endogenous 7-dehydrocholesterol content was elevated by pretreatment with the sterol Δ7-reductase inhibitor BM15766. Nevertheless, dermal fibroblasts produce inactive vitamin D3 metabolites that can be activated by epidermal keratinocytes as CYP24 mRNA is induced in epidermal keratinocytes but not in dermal fibroblasts after transfer of medium or cellular suspensions from BM15766-pretreated, UVB-irradiated fibroblasts. This CYP24 induction was UVB-dose dependent and was inhibited by ketoconazole. As revealed in a competitive binding assay, BM15766-pretreated dermal fibroblasts are able to produce 25OHD3 upon UVB irradiation, but no 1,25(OH)2D3 was detected via combined high-performance liquid chromatography radioimmunoassay. The physiological relevance of dermal vitamin D3 photoproduction and its subsequent conversion into 25OHD3 remains elusive. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
39. Differential Stimulation of ERK and JNK Activities by Ultraviolet B Irradiation and Epidermal Growth Factor in Human Keratinocytes.
- Author
-
Assefa, Zerihun, Garmyn, Maryan, Bouillon, Roger, Merlevede, Wilfried, Vandenheede, Jackie R., and Agostinis, Patrizia
- Subjects
- *
ULTRAVIOLET radiation , *EPIDERMAL growth factor , *KERATINOCYTES , *SKIN cancer , *PROTEIN kinases , *RADIATION , *GROWTH factors - Abstract
Exposure of mammalian cells to solar ultraviolet (UV) radiation leads to the expression of several genes, and UV has been recognized as a major initiator and promoter of skin cancer. The component of the solar radiation that contributes most to human skin malignancy is UVB (280-320 nm) and, to a lesser extent, UVA (320-400 nm), whereas the high-energy UVC (100-280 nm) is absorbed by the earth's upper atmosphere. Sublethal doses of UVB produce strong induction of c-jun and c-fos transcripts in several cells including human primary keratinocytes. The present report confirms that this is also the case in the HaCaT cell line and shows that similar UVB doses are potent inducers of the JNK/SAPK family of mitogen-activated protein kinases but only weak activators of ERKs. Epidermal growth factor (EGF) caused rapid induction of both JNK- and ERK-signaling pathways, and the downmodulation of the EGF-signaling pathway by EGF pre-treatment inhibited the UVB-induced JNK1 activation. Prior UVB irradiation of the cells decreased the level of the ERK2 activation by a subsequent EGF treatment, but this sensitized the cells and allowed for the super-activation of JNK1 after a rechallenge with either UVB or EGF. The antioxidant N-acetylcysteine impaired the UVB- and EGF-induced activation of JNK1. Our data suggest the presence of shared signaling component(s) in the UVB- and EGF-induced cellular response pathways and imply that oxidative stress plays a significant role in the activation of JNK1 by UVB and EGF. [ABSTRACT FROM AUTHOR]
- Published
- 1997
- Full Text
- View/download PDF
40. CD-ring modified vitamin D3 analogs and their superagonistic action
- Author
-
Eelen, Guy, Verlinden, Lieve, Bouillon, Roger, De Clercq, Pierre, Muñoz, Alberto, and Verstuyf, Annemieke
- Subjects
- *
CHOLECALCIFEROL , *STEROIDS , *COLON cancer , *CANCER cells , *GENE expression , *GENE targeting , *NUCLEAR receptors (Biochemistry) - Abstract
Abstract: Non-steroidal analogs of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] represent a most particular class of analogs because they are either not directly derived from the core 1,25(OH)2D3-structure or they have modifications in the core structure that are so drastic that the steroidal structure is lost. Non-steroidal CD-ring analogs of 1,25(OH)2D3 have been developed to study the role of the central rigid CD-ring system in the biological activity of 1,25(OH)2D3. Here we review the different classes of CD-ring analogs and highlight some representative analogs such as the fluorinated D-ring analogs CD578, WU515 and WY1113 which show markedly increased differentiating activity on human SW480-ADH colon cancer cells, characterized by a stronger induction of the invasion suppressor E-cadherin and a stronger repression of the β-catenin/TCF target oncogene c-Myc. Correspondingly, CD578, WU515 and WY1113 are more potent inhibitors of β-catenin/TCF signaling than 1,25(OH)2D3 and induce stronger VDR–coactivator interactions. Underlying the increased biological potency of analog CD578 are additional contacts between the side chain fluorine atoms of the analog with specific residues of helix 12 (H12) of the Vitamin D Receptor (VDR) and subsequent stronger VDR–coactivator interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
41. Vitamin D receptor stimulation to reduce acute respiratory distress syndrome (ARDS) in patients with coronavirus SARS-CoV-2 infections: Revised Ms SBMB 2020_166.
- Author
-
Quesada-Gomez, Jose Manuel, Entrenas-Castillo, Marta, and Bouillon, Roger
- Subjects
- *
VITAMIN D receptors , *ADULT respiratory distress syndrome , *COVID-19 , *CYTOKINE release syndrome , *CORONAVIRUSES - Abstract
• Corona virus infections can cause Acute Respiratory Distress Syndrome (ARDS), mediated by a variety of mechanisms, including cytokine storm, dysregulation of the renin-angiotensin system, neutrophil activation, and the coagulation cascade. • Vitamin D receptor activation act on many cellular and biochemical mechanisms responsible for ARDS. Most data suggest that VDR activation may taper down ARDS. • Vitamin D supplementation, either as vitamin D or calcifediol (25OHD), is being tested in several RCTs as to demonstrate its potential effects on the course of corona virus infections. • A pilot study in Cordoba suggested that calcifediol treatment may reduce the need for ICU treatment of patients hospitalized for COVID19 infections. Coronavirus infection is a serious health problem awaiting an effective vaccine and/or antiviral treatment. The major complication of coronavirus disease 2019 (COVID-19), the Acute Respiratory Distress syndrome (ARDS), is due to a variety of mechanisms including cytokine storm, dysregulation of the renin-angiotensin system, neutrophil activation and increased (micro)coagulation. Based on many preclinical studies and observational data in humans, ARDS may be aggravated by vitamin D deficiency and tapered down by activation of the vitamin D receptor. Several randomized clinical trials using either oral vitamin D or oral Calcifediol (25OHD) are ongoing. Based on a pilot study, oral calcifediol may be the most promising approach. These studies are expected to provide guidelines within a few months. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
42. NOD bone marrow-derived dendritic cells are modulated by analogs of 1,25-dihydroxyvitamin D3
- Author
-
van Etten, Evelyne, Decallonne, Brigitte, Bouillon, Roger, and Mathieu, Chantal
- Subjects
- *
BONE marrow , *DENDRITIC cells , *VITAMIN D , *DIABETES - Abstract
The immune effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) are mainly mediated through dendritic cells (DCs). In vitro, 1,25(OH)2D3 treatment renders murine bone marrow (BM)-derived DCs more tolerogenic, indirectly altering behavior and fate of T lymphocytes. In vivo, treatment with 1,25(OH)2D3 or its analogs prevents diabetes in NOD mice. The aim of this study was to investigate the effects of the 1,25(OH)2D3-analog TX527 on the expression of antigen-presenting and costimulatory/migratory molecules on BM-derived DCs from NOD mice. After culture with 20 ng/ml
GM-CSF+20 ng/ml IL-4 (8 days) followed by 1000 ng/mlLPS+100 U/ml IFN-γ (2 days), with or without 10−8 M TX527, cells were counted and analyzed by FACS for MHC II, CD86, CD40 and CD54 expression within the CD11c+ DC population. Upon TX527 treatment, cell recovery was significantly reduced whereas the CD11c+ DC fraction remained constant. On CD11c+ DCs, MHC II, CD86 and CD54 were significantly down-regulated and CD40 was twofold upregulated. Globally, BM-derived DCs from NOD mice become more tolerogenic upon TX527 treatment, confirming the effects of 1,25(OH)2D3 on murine DCs and possibly explaining the protective effects of 1,25(OH)2D3 and its analogs from diabetes in NOD mice. [Copyright &y& Elsevier]- Published
- 2004
- Full Text
- View/download PDF
43. WY 1048, a 17-methyl 19-nor D-ring analog of vitamin D3, in combination with risedronate restores bone mass in a mouse model of postmenopausal osteoporosis.
- Author
-
Doms, Stefanie, Verlinden, Lieve, Vanhevel, Justine, Janssens, Iris, Bouillon, Roger, De Clercq, Pierre, and Verstuyf, Annemieke
- Subjects
- *
CALCITRIOL , *BONE density , *OSTEOPOROSIS in women , *RETINOIDS , *CHOLECALCIFEROL , *BONES - Abstract
Highlights • WY 1048 is a novel 1,25(OH) 2 D 3 analog with bone protective properties. • WY 1048 in combination with risedronate restores ovariectomy-induced bone loss. • WY 1048 restores bone loss to a greater extent than 1,25(OH) 2 D 3. • Bone loss is restored without causing hypercalcemia or hypercalciuria. Abstract Bisphosphonates like risedronate inhibit osteoclast-mediated bone resorption and are therefore used in the prevention and treatment of osteoporosis. Also vitamin D 3 and calcium supplementation is commonly used in the prevention or treatment of osteoporosis. Combined therapy of risedronate with 1,25(OH) 2 D 3 , the active metabolite of vitamin D 3 , may be advantageous over the use of either monotherapy, but bears a risk of causing hypercalcemia thereby decreasing the therapeutic window for osteoporosis treatment. In this study, we evaluated the effect on bone mass of the combination of risedronate with the 17-methyl 19-nor five-membered D-ring vitamin D 3 analog WY 1048 in a mouse ovariectomy model for postmenopausal osteoporosis. Ovariectomy-induced bone loss was restored by administration of risedronate or a combination of risedronate with 1,25(OH) 2 D 3. However, the combination of WY 1048 with risedronate induced an even higher increase on total body and spine bone mineral density and on trabecular and cortical bone mass. Our data indicate that combination therapy of risedronate with WY 1048 was superior in restoring and improving bone mass over a combination of risedronate with 1,25(OH) 2 D 3 with minimal calcemic side effects. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Highlights from the 20th Workshop on Vitamin D in Orlando, Mar. 28–31, 2017.
- Author
-
Hewison, Martin, Fleet, James C., Demay, Marie B., Christakos, Sylvia, Bouillon, Roger, Welsh, JoEllen, and White, John H.
- Subjects
- *
VITAMIN D , *ADULT education workshops , *CONFERENCES & conventions - Published
- 2018
- Full Text
- View/download PDF
45. 1β,25-Dihydroxyvitamin D3: A new vitamin D metabolite in human serum.
- Author
-
Pauwels, Steven, Jans, Ivo, Billen, Jaak, Heijboer, Annemieke, Verstuyf, Annemieke, Carmeliet, Geert, Mathieu, Chantal, Maestro, Miguel, Waelkens, Etienne, Evenepoel, Pieter, Bouillon, Roger, Vanderschueren, Dirk, and Vermeersch, Pieter
- Subjects
- *
PHYSIOLOGICAL effects of vitamin D , *TANDEM mass spectrometry , *BLOOD serum analysis , *KIDNEY failure , *METABOLITE analysis , *PATIENTS - Abstract
Background The measurement of 1α,25(OH) 2 D 3 in human serum poses a true challenge as concentrations are very low and structurally similar metabolites can interfere. Materials and methods During optimization of our in-house LC–MSMS method for serum 1α,25(OH) 2 D 3 a previously co-eluting isobaric interference was separated. The isobar was identified as 1β,25(OH) 2 D 3 by comparing retention time and fragmentation spectra to standards (other isobaric dihydroxylated vitamin D 3 analogs). 1β,25(OH) 2 D 3 showed specific cluster formation (water), not present in 1α,25(OH) 2 D 3 . 1β,25(OH) 2 D 3 was measured in serum of apparently healthy human volunteers (n = 20), patients with high serum 25-hydroxyvitamin D [25(OH)D] concentrations (>50 ng/mL) (n = 33 among which 4 with very high levels (>150 ng/mL)) and patients with kidney failure (n = 68; 39 stage 1–3, 29 stage 4–5). Pearson’s r was calculated for correlations and Mann-Whitney statistic to compare group medians. Results Median serum 1β,25(OH) 2 D 3 was 11 pg/mL in apparently healthy volunteers and increased to 20 pg/mL for serum 25(OH)D concentrations above 80 ng/mL (n = 22) (p < 0.0001). 1β,25(OH) 2 D 3 concentrations were significantly correlated to serum 25(OH)D concentrations (r = 0.85) for the combined results from healthy volunteers and patient sera (n = 53) (p < 0.0001). For patients with kidney failure, median serum 1β,25(OH) 2 D 3 was 7 pg/mL and not different from the median level in healthy volunteers (p = 0.06). The median concentration did not vary with different stages. Conclusions We present evidence for the widespread presence of 1β,25(OH) 2 D 3 , a new vitamin D metabolite, in human serum. The level increases with rising serum 25(OH)D concentrations and is particularly high in patients with very high 25(OH)D levels. We previously demonstrated that 1β,25(OH) 2 D 3 is a poor genomic agonist but a potent non-genomic antagonist of 1α,25(OH) 2 D 3. The clinical implications of the presence of this analog therefore require further exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
46. Highlights from the 19th Workshop on Vitamin D in Boston, March 29–31, 2016.
- Author
-
Christakos, Sylvia, White, John H., Hewison, Martin, Welsh, Joellen, Lips, Paul, Bouillon, Roger, and Demay, Marie B.
- Subjects
- *
VITAMIN D , *RESEARCH , *EPIDEMIOLOGY , *MYCOBACTERIAL diseases , *AUTOPHAGY , *CONFERENCES & conventions - Published
- 2017
- Full Text
- View/download PDF
47. Prevention and consequences of vitamin D deficiency in pregnant and lactating women and children: A symposium to prioritise vitamin D on the global agenda.
- Author
-
Schoenmakers, Inez, Pettifor, John M., Peña-Rosas, Juan-Pablo, Lamberg-Allardt, Christel, Shaw, Nick, Jones, Kerry S., Lips, Paul, Glorieux, Francis H., and Bouillon, Roger
- Subjects
- *
VITAMIN D deficiency , *PREGNANCY complications , *CHILD nutrition , *RICKETS prevention , *CONFERENCES & conventions , *PREVENTION - Abstract
The Department of Nutrition for Health and Development of the World Health Organization (WHO) in collaboration with the Executive Committee of the 18th Vitamin D Workshop (VDW), organised a joint symposium on the prevention and consequences of vitamin D deficiency in pregnant women and children, convening experts on vitamin D, clinicians and policy-makers. The overall aim was to identify priority areas for research and to discuss the need for global options for policy, with a focus on the prevention of rickets in infants and children and vitamin D deficiency in pregnant women. The scope and purpose were: (i) to present the WHO research strategy for health, addressing vitamin D-related public health problems and the process for the development of evidence-informed guidelines in general and how vitamin D interventions in diverse populations could be prioritised; (ii) to provide an overview of vitamin D status in children and pregnant and lactating women across the world; (iii) to review the health risks associated with vitamin D deficiency in children and in pregnant women and their offspring; (iv) to understand the aetiology of vitamin D deficiency in pregnant women and children; (v) to identify and interpret biomarkers to assess vitamin D status and to consider possible clinical and biochemical screening tools for determining the prevalence of nutritional rickets in at risk groups or communities; and (vi) to provide an overview of policies and recommendations on vitamin D across the world. The format of the symposium was a composite of comprehensive scientific presentations and a panel debate with international experts on WHO guidelines, nutritional rickets, nutritional policy and consequences of vitamin D deficiency during pregnancy. This paper summarizes the content and outcomes of the panel debate. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
48. Fifteenth Vitamin D Workshop.
- Author
-
Norman, Anthony W., Bikle, Daniel, and Bouillon, Roger
- Published
- 2013
- Full Text
- View/download PDF
49. Highlights from the 18th workshop on vitamin D, Delft, The Netherlands, April 21–24, 2015.
- Author
-
Lips, Paul, Welsh, JoEllen, Demay, Marie, and Bouillon, Roger
- Subjects
- *
VITAMIN D , *EPIDEMIOLOGY , *DIETARY calcium , *KIDNEY physiology , *RICKETS , *CONFERENCES & conventions - Published
- 2016
- Full Text
- View/download PDF
50. 1,25-Dihydroxyvitamin D3 and the aging-related Forkhead Box O and Sestrin proteins in osteoblasts.
- Author
-
Eelen, Guy, Verlinden, Lieve, Meyer, Mark B., Gijsbers, Rik, Pike, J. Wesley, Bouillon, Roger, and Verstuyf, Annemieke
- Subjects
- *
CHOLECALCIFEROL , *FORKHEAD transcription factors , *OSTEOBLASTS , *PHYSIOLOGICAL stress , *IMMUNOPRECIPITATION , *GENETIC regulation - Abstract
Abstract: Forkhead Box O (FoxO) transcription factors and Sestrins (SESN) are highly conserved and related stress-responsive proteins that protect the organism against age-related pathologies. For FoxOs, growing evidence shows a crucial role in osteoblast function. Here we investigated the role of different FoxO and SESN isoforms in 1,25(OH)2D3-treated MC3T3-E1 osteoblasts. 1,25(OH)2D3 rapidly and strongly induced the expression of SESN1 and FoxO3a but down-regulated the expression of SESN3 and FoxO1. SESN2 and FoxO4 levels were hardly affected by 1,25(OH)2D3. Chromatin Immunoprecipitation (ChIP)-sequencing revealed significant VDR/RXR binding to a DR3-type VDRE in SESN1 but not in the genomic region where FoxO3a is located. Mutation of the SESN1 VDRE abolished responsiveness to 1,25(OH)2D3 in luciferase-based transfection assays. siRNA-mediated knock-down of SESN1, SESN3, FoxO1 or FoxO3a did not prevent 1,25(OH)2D3 from reducing the expression of cell cycle markers like Cyclin D1 and Cdc6 and from exerting its characteristic antiproliferative effect on MC3T3-E1 osteoblasts. Accordingly, the 1,25(OH)2D3-induced reduction in the number of S-phase cells was also maintained. The antiproliferative effect was still present in primary osteoblast in which all three FoxO isoforms were deleted (TKOpOB). Interestingly, both MC3T3-E1 osteoblasts in which FoxO1 was knocked-down and TKOpOBs accumulated significantly more reactive oxygen species (ROS) after treatment with 1,25(OH)2D3 than control cells. siRNA-mediated knock-down of individual SESN isoforms did not result in significant differences in ROS levels. In conclusion, 1,25(OH)2D3 directly and indirectly alters the expression levels of different FoxO and SESN isoforms in osteoblasts, presumably not to exert its antiproliferative action but to control ROS levels. This article is part of a Special Issue entitled ‘Vitamin D Workshop’. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.