Vitamin A Intake, Serum Vitamin D and Bone Mineral Density: Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2011)

The association of high vitamin A intake and low bone mineral density (BMD) is still controversial. To determine the association of dietary vitamin A intake and serum 25-hydroxyvitamin D (25(OH)D) concentration with BMD, a total of 6481 subjects (2907 men and 3574 women) aged >= 50 years from the Korean National Health and Nutrition Examination Survey (2008-2011) were divided into groups according to dietary vitamin A intake (tertiles) and serum 25(OH)D (<50, 50-75, >75 nmol/L), and evaluated for BMD after adjusting for relevant variables. Mean dietary vitamin A intakes were 737 and 600 mu g RE (Retinol Equivalents) in men and women, respectively. Total hip and femoral neck BMD in men and lumbar spine BMD in women were both positively correlated with dietary vitamin A intake in subjects with serum 25(OH)D >75 nmol/L. Among men with serum 25(OH)D <50 nmol/L, both the top (mean 1353 mu g RE) and bottom (mean 218 mu g RE) tertiles of dietary vitamin A intake had lower BMD than the middle group (mean 577 mu g RE). In this population, BMD was the highest among men and women with serum 25(OH)D = 50-75 nmol/L and that there were no differences in BMD by vitamin A intake in these vitamin D adequate groups. This cross-sectional study indicates that vitamin A intake does not affect bone mineral density as long as the serum 25(OH)D concentration is maintained in the moderate level of 50-75 nmol/L.