The present invention relates generally to the use of
vitamin B12 (
cobalamin or
cyanocobalamin) alone or in combination with other photoprotective agents, including specifically other vitamins such as
vitamin B9 (
folic acid or folate) and
vitamin B3 (
niacin or
niacinamide), or any chemical derivative of these vitamins and their salts, as a filter to protect cells against the damaging effects of
ultraviolet (UV) light. The invention is, in one aspect, a method of reducing the rate of UV damage to cells exposed to a UV
light source, by treating the cells with the vitamin composition, either alone or in combination with other photoprotective agents. Other aspects of the invention are compositions comprising effective amounts of
vitamin B12 alone or in combination with other photoprotective agents including
vitamin B9 and
vitamin B3 and a pharmaceutically-acceptable carrier, that are useful in protecting cells, particularly
skin cells, against the burning, genotoxic (mutagenic and carcinogenic), immunosuppressive and
photoaging effects of UV light, especially
sunlight. The invention has application as a UV
light filter in oral preparations including tablets and drinks, topical creams, lotions, sprays, wipes and
cosmetics. The invention also has application as a medicinal treatment for dermatological conditions caused by
exposure to
sunlight, such as
actinic keratoses, photodermatitis, photo-induced (discoid)
lupus erythematosus and the photosensitizing effects of a variety of drugs used commonly in clinical practice (e.g. certain antihistamines, ACE inhibitors, and
antibiotics such as
tetracycline).