The goals were to determine the prevalence of vitamin D deficiency among minority children in a southern US city, to examine differences in serum 25-hydroxyvitamin D levels between non-Hispanic black and Hispanic children, and to determine dietary sources of vitamin D.
Low-income, minority children (N = 290; mean age: 2.5 ± 1.2 years) were recruited during well-child clinic visits. Serum 25-hydroxyvitamin D and calcium levels were measured and dietary information was assessed.
The mean 25-hydroxyvitamin D3 level was 26.2 ± 7.6 ng/mL, whereas 25-hydroxyvitamin D2 was not detected. Overall, 22.3% of children had deficient serum 25-hydroxyvitamin D3 levels (≤20 ng/mL), 73.6% had less-than-optimal serum 25-hydroxyvitamin D levels (≤30 ng/mL), and 1.4% had low serum calcium levels (≤9 mg/dL). A significantly larger proportion of non-Hispanic black children, compared with Hispanic children, had vitamin D deficiency (26% vs 18%; P < .05). Age and season of recruitment were significantly associated with vitamin D deficiency and low serum calcium levels. Older children (≥3 years) were less likely to have vitamin D deficiency (odds ratio [OR]: 0.89 [95% confidence interval [CI]: 0.81–0.96]; P < .001). Study enrollment during spring and summer reduced the likelihood of vitamin D deficiency by ∼20% (spring, OR: 0.85 [95% CI: 0.73–0.98]; P = .03; summer, OR: 0.82 [95% CI: 0.73–0.92]; P < .01). Fortified milk provided most dietary vitamin D (62%), with Hispanic children reporting greater intake.
Suboptimal vitamin D status was common among apparently healthy, low-income, minority children. Age and season were significant predictors of vitamin D deficiency.