About vitamin D
Vitamin D is a fat-soluble compound essential for calcium metabolism in animals and therefore important for normal mineralization of bone and cartilage. The skin forms vitamin D when exposed to sunlight, but in some circumstances sunlight may lack sufficient amounts of ultraviolet rays to bring about adequate production of the vitamin.
Vitamin D is a fat-soluble compound essential for calcium metabolism
Deficiencies cause many biochemical and physiological imbalances. If uncorrected, faulty mineralization of bones and teeth causes rickets in growing children and osteomalacia (progressive loss of calcium and phosphorus from the bones) in adults. Common early symptoms of rickets include restlessness, profuse sweating, lack of muscle tone in the limbs and abdomen, and delay in learning to sit, crawl, and walk. Rickets may produce such conditions as bowlegs and knock-knees. Deficiency may also cause osteoporosis, a bone condition characterized by an increased tendency of the bones to fracture. Large doses of vitamin D are toxic, and symptoms include weakness, loss of appetite, nausea, vomiting, diarrhea, excessive thirst, and weight lossVitamin D
Food sources
There are only a few foods which contain vitamin D. These include oily fish, fish oils, butter and eggs. Some foods, like margarine, evaporated milk and breakfast cereals are fortified with vitamin D.Unlike other vitamins, we can actually make vitamin D in our bodies as a result of exposure to sunlight, providing the necessary starting materials are there. Vitamin D is a fat soluble vitamin that can be stored in the body. This means that our bodies can use these stores if levels are not topped up every day. Vitamin D is vital for general wellbeing and, in particular, for healthy bones and teeth.Deficiency
A deficiency of vitamin D in children can lead to rickets. This means that the bones are not formed correctly because the lack of vitamin D does not allow enough calcium to be absorbed.Adults who are deficient in vitamin D may suffer from osteomalacia (thinning of the bones). A lack of vitamin D may also prevent adequate adsorption of calcium and contribute to Osteoporosis.Vitamin D and lifestyle
There may be a shortage of vitamin D, especially in northern countries such as Great Britain, among adults who do not get outdoors regularly or whose skin is not exposed to sunlight because of cultural dress restrictions.Vitamin D is important throughout life. Since it is necessary for calcium absorption, supplements are available for children under five and for pregnant and breastfeeding women. These supplements are free of charge for those in need. As we get older, our bodies are not able to absorb vitamin D or make it in the skin so efficiently. Recent research indicates that older people with a good regular supply of vitamin D and calcium may be less likely to suffer fractures due to brittle or thinning bones. Older people should therefore try to eat more foods rich in vitamin D.
