Vitamin D deficiency in minority populations

Public Health Nutr. 2015 Feb;18(3):379-91. doi: 10.1017/S1368980014000457. Epub 2014 Apr 15.

Abstract

Objective: Black and Hispanic individuals synthesize less vitamin D per unit of sun exposure than white individuals. The relationship between UV radiation and vitamin D insufficiency in minorities has not been well explored.

Design: Prospective cohort study.

Setting: Using the National Health and Nutrition Examination Survey, we obtained serum vitamin D levels for non-Hispanic Whites, Hispanics and non-Hispanic Blacks aged ≥18 years from 2000-2006. We linked these data with the average monthly solar UV index by census tract and data on sun exposure, vitamin D supplementation, health and demographics. We used multivariable regression analyses to assess vitamin D deficiency (<15 ng/ml) and insufficiency (<20 ng/ml) in January (when the UV index was lowest) by race/ethnicity and geography.

Subjects: Adults (n 14,319) aged ≥18 years.

Results: A 1-point increase in the UV index was associated with a 0·51 ng/ml increase in vitamin D (95% CI 0·35, 0·67 ng/ml; P<0·001). Non-Hispanic Black race and Hispanic ethnicity were associated with a 7·47 and 3·41 ng/ml decrease in vitamin D, respectively (both P<0·001). In January, an estimated 65·4% of non-Hispanic Blacks were deficient in vitamin D, compared with 28·9% of Hispanics and 14·0% of non-Hispanic Whites. An estimated 84·2% of non-Hispanic Blacks were insufficient in vitamin D v. 56·3% of Hispanics and 34·8% of non-Hispanic Whites. More non-Hispanic Blacks were estimated to be deficient in vitamin D in January in the highest UV index quartile than were non-Hispanic Whites in the lowest UV index quartile (60·2% v. 25·7%).

Conclusions: Wintertime vitamin D insufficiency is pervasive among minority populations, and not uncommon among non-Hispanic Whites.

Keywords: Disparities; Race; Survival; Vitamin D; Vitamins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • African Americans
  • Aged
  • Calcifediol / blood*
  • Cohort Studies
  • European Continental Ancestry Group
  • Health Status Disparities*
  • Hispanic Americans
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Minority Health* / ethnology
  • Prospective Studies
  • Seasons
  • Spatio-Temporal Analysis
  • Sunlight
  • United States / epidemiology
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D Deficiency / ethnology
  • Vitamin D Deficiency / prevention & control
  • Young Adult

Substances

  • Calcifediol