Natural vitamin D (D3, cholecalciferol) reaches the body from animal sources in the diet and from endogenous skin synthesis by the action of solar ultraviolet irradiation. Vitamin D2 (ergocalciferol) is used for fortifying proprietary foods such as margarine (and milk in the USA and Canada). These compounds have equal potency in man. A regular intake of 2.5 micrograms (100 i.u.) daily for adults and about 10 micrograms (400 i.u.) daily for children under 5 years old is usually recommended to prevent nutritional osteomalacia and rickets.
Solar Ultraviolet Irradiation Induces Decorin Degradation in Human Skin Likely via Neutrophil Elastase
