Vitamin D insufficiency among African-Americans in the southeastern United States: implications for cancer disparities (United States).
OBJECTIVE
To determine the prevalence and predictors of vitamin D insufficiency among black and white adult residents of the southern US.


METHODS
A cross-sectional analysis of serum 25(OH)D levels using baseline blood samples from 395 Southern Community Cohort Study (SCCS) participants. Participants were African-American and white adults aged 40-79 who enrolled in the study from 2002-2004. We defined hypovitaminosis D as serum 25(OH)D levels < or = 15 ng/ml.


RESULTS
Hypovitaminosis D prevalence was 45% among blacks and 11% among whites. Vitamin D intake from diet and supplements was associated with modest increases in circulating 25(OH)D (0.5-0.7 ng/ml per 100 IU increment), but hypovitaminosis D was found for 32% of blacks with intake > or = 400 IU/day. Body mass index (BMI) was a strong predictor of risk for hypovitaminosis D among black women (OR = 6.5, 95% CI 1.7-25.1 for BMI > or = 30 kg/m(2) vs. 18-24.9 kg/m(2)). UVR exposure estimated by residential location was positively associated with 25(OH)D levels among all groups except white women.


CONCLUSIONS
Hypovitaminosis D was present in a substantial proportion of the African-American population studied, even in the South and among those meeting recommended dietary guidelines. Vitamin D should continue to be a studied target for ameliorating racial cancer disparities in the US.
Egan
Kathleen M
KM
Vanderbilt University Medical Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA.
Signorello
Lisa B
LB
Munro
Heather M
HM
Hargreaves
Margaret K
MK
Hollis
Bruce W
BW
Blot
William J
WJ
D000328:Adult; D001741:Black or African American; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies; D014481:United States / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000208:ethnology*