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Objective: To determine whether African American children with forearm fractures have decreased bone mineral density and an increased prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D level ≤ 20 ng/mL) compared with fracture-free control patients., Methods: This case-control study in African American children, aged 5 to 9 years, included case patients with forearm fracture and control patients without fracture. Evaluation included measurement of bone mineral density and serum 25-hydroxyvitamin D level. Univariable and multivariable analyses were used to test for associations between fracture status and 2 measures of bone health (bone mineral density and 25-hydroxyvitamin D level) while controlling for other potential confounders., Results: The final sample included 76 case and 74 control patients. There were no significant differences between case and control patients in age, gender, parental education level, enrollment season, outdoor play time, height, or mean dietary calcium nutrient density. Cases were more likely than control patients to be overweight (49.3% vs 31.4%, P = .03). Compared with control patients, case patients had lower whole body z scores for bone mineral density (0.62 ± 0.96 vs 0.98 ± 1.09; adjusted odds ratio 0.38 [0.20-0.72]) and were more likely to be vitamin D deficient (47.1% vs 40.8%; adjusted odds ratio 3.46 [1.09-10.94])., Conclusions: These data support an association of lower bone mineral density and vitamin D deficiency with increased odds of forearm fracture among African American children. Because suboptimal childhood bone health also negatively impacts adult bone health, interventions to increase bone mineral density and correct vitamin D deficiency are indicated in this population to provide short-term and long-term benefits.

We sought to investigate the relationship between newly identified genetic variants and vitamin D levels and fracture risk in healthy African American (black) children. This case-control study included children of both sexes, ages 5 to 9 years, with and without forearm fractures. Serum 25-hydroxy vitamin D levels, bone mineral density, body mass index, and calcium/vitamin D intake were measured in 130 individuals (n = 60 cases and n = 70 controls). The 5 variants tested were located in the GC gene (rs2282679), in the NADSYN1 gene (rs12785878 and rs3829251), and in the promoter region of the CYP2R1 gene (rs2060793 and rs104741657). Associations between single nucleotide polymorphisms (SNPs) and vitamin D levels were tested using an analysis of covariance. Associations between SNPs and fracture status were tested using logistic regression. The GC gene variant was associated with vitamin D levels (P = 0.038). None of the SNPs were associated with fracture status in young blacks. These results suggest that the variants tested, which are associated with circulating vitamin D levels in whites, are not associated with fracture status in healthy black children. Additional research is required to discover the genetics of fracture risk in blacks.