Vitamin D - what is it?
Vitamin D, New RDA* 5 µg
Vitamin D is a fat-soluble vitamin. This means you don't need it every day because any of the vitamins your body doesn't need immediately is stored for future use.
Vitamin D3 (cholecalciferol) is produced photochemically from 7-dehydrocholesterol in the skin by exposure to sunlight or ultraviolet light. Vitamin D2 is formed similarly from ergosterol in plants, fungi and lower life forms.
*Sourced from EFSA WEBSITE
Vitamin D - what does it do?
Needed for the absorption of calcium and phosphorus from foods, to keep bones healthy.
Recent research also suggests that vitamin D enhances immune function and improves muscle strength.
Deficiency
Prolonged vitamin D deficiency in infants and children results in rickets. In adults, vitamin D deficiency results in osteomalacia, the clinical symptoms of which include skeletal pain and muscle weakness and pathological fractures. Less severe vitamin D deficiency (usually referred to as vitamin D insufficiency) is associated with secondary hyperparathyroidism and increased bone loss, leading to high risk of fractures. Groups such as black, Asian, institutionalised older people, and those who habitually cover the skin may form less vitamin D endogenously as a result of exposure to sunlight, and are vulnerable to vitamin D deficiency. Individuals with a decreased capacity for intestinal absorption of vitamin D, for example following partial gastrectomy, are also at increased risk of vitamin D deficiency, as are patients with liver, renal and cardiopulmonary diseases.
Vitamin D - Sources
Oily fish, eggs, fortified cereals and margarine.
Most is obtained through the action of sunlight on our skin during the summer months.