Serum 25-hydroxyvitamin D status of vegetarians, partial vegetarians, and nonvegetarians: the Adventist Health Study-2

Background: Vegans and other vegetarians who limit their intake of animal products may be at greater risk of vitamin D deficiency than nonvegetarians, because foods providing the highest amount of vitamin D per gram naturally are all from animal sources, and fortification with vitamin D currently occurs in few foods. Objective: We assessed serum 25-hydroxyvitamin D [s25(OH)D] concentrations and factors affecting them in vegetarians, partial vegetarians, and nonvegetarians in a sample of calibration study subjects from the Adventist Health Study-2. Design: Food-frequency questionnaires and sun-exposure data were obtained from 199 black and 229 non-Hispanic white adults. We compared s25(OH)D concentration, dietary and supplemental vitamin D intake, and sun exposure in the different dietary groups. Results: We found no significant difference in s25(OH)D by vegetarian status for either white or black subjects. Among whites, dietary vitamin D intake and sun behavior were different between vegetarian groups, but there was no difference in skin type distribution. Among blacks, no significant differences were observed for any of these variables between vegetarian groups. The mean (+/- SD) s25(OH)D was higher in whites (77.1 +/- 10.33 nmol/L) than in blacks (50.7 +/- 27.4 nmol/ L) ( P < 0.0001). Conclusions: s25(OH)D concentrations were not associated with vegetarian status. Other factors, such as vitamin D supplementation, degree of skin pigmentation, and amount and intensity of sun exposure have greater influence on s25( OH) D than does diet. Am J Clin Nutr 2009; 89(suppl): 1686S-92S.