June 1, 2009Journal of the American College of Nutrition
Vitamin D3Distribution and Status in the Body
Authors
Discussion
Loading...
Member takes
Implication
Translational tissue analysis reveals limited body reserves of vitamin D3, suggesting current dietary recommendations are substantially underestimated.
Key Points
- To estimate the total quantity, chemical forms, and tissue distribution of vitamin D in the adult body under typical dietary inputs.
- Reviewed and reanalyzed published human measurements alongside HPLC analysis of tissue samples from growing pigs raised on diets providing ~2000 IU vitamin D/day.
- Total body vitamin D at a mean serum 25(OH)D of 45 nmol/L was estimated at 14,665 IU for a 70 kg adult woman, composed of 65% native cholecalciferol and 35% 25(OH)D.
- Approximately 75% of native cholecalciferol resided in fat, whereas 25(OH)D was distributed across fat (35%), serum (30%), muscle (20%), and other tissues (15%).
- Total body reserves accounted for only an estimated 7-day supply at typical daily utilization rates of roughly 2000 IU/day.
Cite This Study
Heaney et al. (2009) studied this question.