- On average, the daily dietary intake of Vitamin D for men and women is 3.7 mcg and 2.8 mcg respectively
- UVB during the winter months is insufficient to produce adequate concentrations of Vitamin D. Individuals must therefore rely on Vitamin D stored in body fat, in supplements and in a healthy diet.
- Available data suggests that long term supplementation of less than 1000 IU (25 mcg) per day is safe
- The US Food and Nutrition Board established 2000 IU (50 mcg) per day as a safe Tolerable Upper Intake Level (UL)
- No high quality data exists on the safety of long term supplementation of more than 1000 IU (25 mcg)
- However, recent evidence from medium to long term studies indicate that upper intake levels up to 10000 IU (250 mcg) per day may be deemed as safe