Vitamin D3 enhances calcium absorption and retention, a key
nutritional role in supporting healthy bones, and may play a potential
role in cardiovascular, colon and cellular health. Vitamin D levels
have been shown to decline with age, due primarily to a reduction in
either absorption or metabolism by the liver. Decreased exposure to
sunlight, a vegetarian diet, or a low intake of vitamin D fortified foods
also play a role in inadequate vitamin D levels.