Vitamin D status, adiposity, and lipids in black American and Caucasian children

Abstract

Objective: The aim of the study was to examine the relationship between vitamin D status, total and abdominal adiposity, and lipids in black and white children.

Methods: Plasma 25-hydroxyvitamin D [25(OH)D], adiposity [body mass index (BMI), percentage of total body fat, visceral adipose tissue (VAT), sc adipose tissue (SAT)], and fasting lipids were assessed in healthy obese and nonobese 8- to 18-yr-old black and white children.

Results: We studied 237 children (mean ± sd age, 12.7 ± 2.2 yr; 47% black, 47% obese, and 43% male). Mean 25(OH)D concentration for the entire cohort was 19.4 ± 7.4 ng/ml. The majority of the children were vitamin D deficient [25(OH)D < 20 ng/ml; 73% blacks, 40% whites]. Plasma 25(OH)D was associated inversely with BMI, BMI percentile, percentage of total body fat, VAT, and SAT and positively with HDL cholesterol in the entire cohort. VAT was higher in vitamin D-deficient whites, and SAT was higher in vitamin D-deficient blacks compared with their respective vitamin D-nondeficient counterparts. Race, season, pubertal status, and VAT were independent significant predictors of 25(OH)D status.

Conclusions: In black and white youth examined together, lower levels of 25(OH)D are associated with higher adiposity measures and lower HDL. Furthermore, vitamin D deficiency is associated with higher VAT in whites and greater SAT in blacks. Besides therapeutic interventions to correct the high rates of vitamin D deficiency in youth, benefits of vitamin D optimization on adiposity measures and lipid profile need to be explored.

Fig. 1.

Vitamin D status (deficient, insufficient, and sufficient) by race.

Fig. 2.

Seasonal variation in plasma 25(OH)D by race. Mann-Whitney U test for 25(OH)D values in winter/spring vs. summer/fall in whites and blacks.

Fig. 3.

Correlations between plasma 25(OH)D levels and BMI, %BF, VAT, SAT, and HDL cholesterol in white (A–E) and black (F–J) youth. In blacks, the “r” and “P” values for the correlation analyses with and without an outlier with high plasma 25(OH)D (arrow) are shown.