Mitchell et al., Endocr. Pract., 2012, 18:6, 914–923,
doi:10.4158/EP12072.OR (Peer Reviewed) (Related)
Prevalence and predictors of vitamin D deficiency in healthy adults
Study of 634 healthy volunteers showing 64% had 25(OH)D ≤ 30 ng/mL. Gender, ethnicity, and multivitamin use were significantly associated with 25(OH)D levels.
Mitchell et al., 1/1/2012, peer-reviewed, 4 authors.