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Background: Dietary calcium intake in rural Gambian women is very low (~350 mg/d) compared with international recommendations. Studies have suggested that calcium supplementation of women receiving low-calcium diets significantly reduces risk of pregnancy hypertension. Objective: We tested the effects on blood pressure (BP) of calcium carbonate supplementation (1500 mg Ca/d) in pregnant, rural Gambian women. Design: The study was a randomized, double-blind, parallel, placebo-controlled supplementation trial from 20 wk of gestation (P20) until delivery (calcium: n = 330; placebo; n = 332). BP and anthropometric measures were taken at P20 and then 4 weekly until 36 wk of gestation (P36), and infant anthropometric measures were taken at 2, 13, and 52 wk postdelivery. Results: A total of 525 (calcium: n = 260; placebo: n = 265) women had BP measured at P36 and subsequently delivered a healthy term singleton infant. Mean compliance was 97%, and urinary calcium measures confirmed the group allocation. At P20, the mean (±SD) systolic blood pressure (SBP) was 101.2 ± 9.0 and 102.1 ± 9.3 mm Hg, and diastolic blood pressure (DBP) was 54.5 ± 7.3 and 55.8 ± 7.8 mm Hg, in the calcium and placebo groups, respectively. The intention-to-treat analysis that was adjusted for confounders showed no significant effect of calcium supplementation on the change between P20 and P36 (calcium compared with placebo; mean 6 SEM) in SBP (20.64 ± 0.65%; P = 0.3) or DBP (20.22 ± 1.15%; P = 0.8). There was no significant effect of supplementation on BP, pregnancy weight gain, weight postpartum, or infant weight, length, and other measures of growth. However, the comparability of the original randomly assigned groups may have been compromised by the exclusion of 20.7% of women from the final analysis. Conclusions: Calcium supplementation did not affect BP in pregnancy. This result may have been because the Gambian women were adapted to a low dietary calcium intake, and/or obesity, high gestational weight gain, high underlying BP, tobacco use, alcohol consumption, and sedentary lifestyles were rare. This trial was registered at the International Standard Randomized Controlled Trial Register (www. controlled-trials.com/mrct/) as ISRCTN96502494. [ABSTRACT FROM AUTHOR]

Background: Calcium supplementation of pregnant Gambian women with a low calcium intake results in lower maternal bone mineral content in the subsequent lactation. Objective: The objective was to investigate whether the lower bone mineral content persists long term. Design: All women in the calcium supplementation trial (International Trial Registry ISRCTN96502494) who had been scanned with dual-energy X-ray absorptiometry at 52 wk of lactation (L52; n = 79) were invited for follow-up when neither pregnant nor lactating for >3 mo (NPNL) or at 52 wk postpartum in a future lactation (F52). Bone scans and anthropometric and dietary assessments were conducted. Results: Sixty-eight women participated (35 at both NPNL and F52 and 33 at only one time point): n = 59 NPNL (n = 31 calcium, n = 28 placebo) and n = 44 F52 (n = 24 calcium, n = 20 placebo). The mean (±SD) time from L52 was 4.9 ± 1.9 y for NPNL and 5.0 ± 1.3 y for F52. Size-adjusted bone mineral content (SA-BMC) was greater at NPNL than at L52 in the placebo group (P < 0.001) but not in the calcium group (P for time-by-group interaction: lumbar spine, 0.002; total hip, 0.03; whole body, 0.03). No significant changes in SA-BMC from L52 to F52 were observed in either group. Consequently, the lower SA-BMC in the calcium group at L52 persisted at NPNL and F52 (P < 0.001): NPNL (lumbar spine, -7.5 ± 0.7%; total hip, -10.5 ± 1.0%; whole body, -3.6 ± 0.5%) and F52 (lumbar spine, -6.2 ± 0.9%; total hip, -10.3 ± 1.4%; whole body, -3.2 ± 0.6%). Conclusion: In rural Gambian women with a low-calcium diet, a calcium supplement of 1500 mg/d during pregnancy resulted in lower maternal bone mineral content in the subsequent lactation that persisted long term. This trial was registered at www/controlled-trials.com/mrcl/ as ISRCTN96502494. [ABSTRACT FROM AUTHOR]

The article reports on a study examining whether the maternal vitamin D deficiency during pregnancy is a risk factor for rickets and osteomalacia in Gambian infants. As reported, vitamin D status is measured by the circulating plasma concentration of 25-hydroxyvitamin D (25OHD). The study says that no evidence was found for an influence of vitamin D status during pregnancy on infant growth and bone mineral accrual in the conditions prevailing in Gambia.

Abstract: Fracture risk is determined by bone mass, size and architecture. Birth weight (Bwt) is reported to predict adult bone mass and density. Early life environment may therefore be a determinant of bone strength in later life. However such evidence was obtained using dual energy X-ray absorptiometry (DXA), which is known to be dependent on size. We used peripheral quantitative computed tomography (pQCT) and DXA to investigate Bwt as a determinant of bone size and cross section area (CSA), bone mineral content (BMC) and volumetric bone mineral density (vBMD) and areal BMD (aBMD) independent of current weight, height and age. The study population consisted of 68 males and 52 nulliparous females aged 17 to 21years from Keneba, The Gambia. This population has a high prevalence of factors likely to influence skeletal development (poor nutrition, low calcium intake, late puberty and high physical activity). Measures of bone size and CSA, BMC and BMD were obtained using pQCT (Stratec 2000; at 4% and 66% radius; 4% and 50% tibia) and DXA (Lunar DPX; spine, hip, forearm and whole body). Sequential univariable (influence of Bwt on bone variables) and multivariable linear regression analyses (influence of Bwt on bone variables after adjusting for current height, weight and age) were used to investigate the independent effects of Bwt and attained size. Analyses were performed separately by sex. Bwt was a significant positive predictor of CSA at appendicular cortical sites in males and CSA and bone area at appendicular and most axial trabecular sites in females before and after adjustment for current height, weight and age. Bwt was not consistently related to BMC, vBMD or aBMD as measured by pQCT or DXA. Current weight was a positive predictor of aBMD and pQCT- and DXA-derived BMC in males and females. Height predicted aBMD and trabecular vBMD in males. In summary, Bwt significantly predicted attained CSA at cortical sites in males and at trabecular sites in females. Current weight was a positive predictor of BMC and aBMD in both sexes. This suggests that pre-natal factors affecting fetal growth may influence adult bone strength independently of post-natal factors. [Copyright &y& Elsevier]

Background: The World Health Organization recommends calcium supplementation (1500-2000 mg/d) during pregnancy for women with a low-calcium intake., Objectives: The purpose of this study was to investigate whether pregnancy calcium supplementation affects offspring blood pressure and growth in The Gambia where calcium intakes are low (300-400 mg/d)., Methods: Follow-up of offspring born during a randomized controlled trial of pregnancy calcium supplementation (ISRCTN96502494, 1996-2000) in which mothers were randomly assigned to 1500 mg Ca/d (Ca) or placebo (P) from 20 wk pregnancy to delivery. Offspring were enrolled at age 3 y in studies where blood pressure and anthropometry were measured under standardized conditions at approximately 2-yearly intervals. Mean blood pressure and growth curves were fitted for females and males separately, using the longitudinal SuperImposition by Translation and Rotation (SITAR) mixed effects model. This generates 3 individual-specific random effects: size, timing, and intensity, reflecting differences in size, age at peak velocity, and peak velocity through puberty relative to the mean curve, respectively., Results: Five hundred twenty-three singleton infants were born during the trial (maternal group assignment: Ca/P = 259/264). Four hundred ninety-one were enrolled as children (females: F-Ca/F-P = 122/129 and males: M-Ca/M-P = 119/121) and measured regularly from 3.0 y to mean age 18.4 y; 90% were measured on ≥8 occasions. SITAR revealed differences in the systolic blood pressure and height curves between pregnancy supplement groups in females, but not in males. F-Ca had lower systolic blood pressure than F-P at all ages (size = -2.1 ± SE 0.8 mmHg; P = 0.005) and lower peak height velocity (intensity = -2.9 ± SE 1.1%, P = 0.009). No significant pregnancy supplement effects were seen for other measures., Conclusions: This study showed, in female offspring, that pregnancy calcium supplementation may lower systolic blood pressure and slow linear growth in childhood and adolescence, adding to evidence of offspring sexual dimorphism in responses to maternal supplementation. Further research is warranted on the long-term and intergenerational effects of antenatal supplementations. This trial was registered at ISRCTN Registry as ISRCTN96502494., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Limited evidence suggests that calcium intake before puberty influences adolescent height growth and the timing of puberty. Such an effect might be particularly marked in populations in whom low calcium intake, stunting, and delayed puberty are common., Objective: The objective was to test whether 12 mo of calcium supplementation at age 8-12 y to increase intakes toward international recommendations had long-term effects on adolescent growth and pubertal development in rural Gambian children., Design: This was a longitudinal study of 160 Gambian boys (n = 80) and girls (n = 80) who had participated in a 12-mo, randomized, double-blind, placebo-controlled, calcium carbonate supplementation trial (1000 mg Ca/d, 5 d/wk) at age 8-12 y. Anthropometric measures were made every 1-2 y until age 21-25 y; pubertal status and menarche data were collected. Repeated-measures ANCOVA and Superimposition by Translation and Rotation Method (SITAR) growth models were used to assess the effects of treatment., Results: In boys, midadolescent height growth was advanced in the calcium group, which resulted in greater stature at a mean age of 15.5 y (mean ± SEM: 2.0 ± 0.8 cm; P = 0.01) and an earlier age of peak height velocity by 7.4 ± 2.9 mo. Subsequently, the calcium group stopped growing earlier (P = 0.02) and was 3.5 ± 1.1 cm shorter (P = 0.002) at a mean age of 23.5 y. Weight and midupper arm circumference paralleled height. No significant effects were observed in girls, but a sex-by-supplement interaction on height growth could not be confirmed., Conclusion: Calcium supplementation of boys in late childhood advanced the age of peak height velocity and resulted in shorter adult stature in a population in whom low calcium intakes and delayed puberty are common. This trial was registered at isrctn.org as ISRCTN28836000.

Background: Growth and bone mineral accretion in Gambian infants are poorer than those in Western populations. The calcium intake of Gambian women is low, typically 300-400 mg Ca/d, and they have low breast-milk calcium concentrations, which result in low calcium intakes for their breastfed infants. A low maternal calcium supply in pregnancy may limit fetal mineral accretion and breast-milk calcium concentrations and thereby affect infant growth and bone mineral accretion., Objective: We investigated the effects of calcium supplementation in Gambian women during pregnancy on breast-milk calcium concentrations and infant birth weight, growth, and bone mineral accretion., Design: A randomized, double-blind, placebo-controlled supplementation study was conducted in 125 Gambian women who received 1500 mg Ca/d (as calcium carbonate) or placebo from 20 wk of gestation until delivery. Infant birth weight and gestational age were recorded. Breast milk was collected, and infant anthropometric and bone measurements were performed at 2, 13, and 52 wk after delivery. Infant bone mineral status was assessed by using single-photon absorptiometry of the radius and whole-body dual-energy X-ray absorptiometry., Results: Compliance with the supplement was high. No significant differences were detected between the groups in breast-milk calcium concentration, infant birth weight, or growth or bone mineral status during the first year of life. A slower rate of increase in infant whole-body bone mineral content and bone area was found in the supplement group than in the placebo group (group x time interaction: P = 0.03 and 0.02, respectively)., Conclusion: Calcium supplementation of pregnant Gambian women had no significant benefit for breast-milk calcium concentrations or infant birth weight, growth, or bone mineral status in the first year of life.

Background: Our randomized, placebo-controlled supplementation study of 160 rural Gambian children aged 8.3-11.9 y showed that an increase in calcium intake of 714 mg/d for 12 mo resulted in a 5% increase in forearm bone mineral acquisition and a 22% decrease in plasma osteocalcin concentration, a bone formation marker, but had no effect on height or bone dimensions., Objective: We investigated whether these results were sustained after supplement withdrawal., Design: All participants were followed up 12 (FU1) and 24 (FU2) mo after supplementation ended. Bone mineral content (BMC), bone mineral density (BMD), and BMC adjusted for bone width, body weight, and height (size-adjusted BMC) were measured at the midshaft and distal radius. Plasma osteocalcin concentration was measured at FU1., Results: At follow-up, the calcium group had greater bone mineral status than did the placebo group at the midshaft radius (mean difference +/- SE), FU1: BMC (4.7 +/- 1.6%; P = 0.004), BMD (5.1 +/- 1.1%; P