Ergocalciferol

A synonym for calciferol and vitamin D2, one of the sterols that constitute vitamin D. It is synthesised by irradiating the plant provitamin ergosterol with ultraviolet light. Used to fortify foods such as milk and margarine to prevent rickets, and sold as a dietary supplement for people with low sun exposure. Unlike vitamin D3 (cholecalciferol) from animal sources and sunlight, D2 suits vegan and vegetarian fortification, though some evidence suggests D3 raises blood 25-hydroxyvitamin D more effectively. Fortification vehicles — milk, margarine, orange juice, cereals — are chosen for wide consumption, and overage allowances compensate for storage losses.