Very little of vitamin D is got from dietary sources. It is a vitamin that is usually taken for granted as it gets produced in the body. UV rays from the sun promote the synthesis of vitamin D in the skin. In cold countries, away from the equator, the risk of developing vitamin D deficiency is more. The body cannot generate too much of the vitamin from exposure to sunlight. It is self-regulatory and generates only what it requires.
As vitamin D gets produced by the skin, the use of sunscreen also reduces its rate of synthesis in the skin. Even those who stay indoors and are not exposed to sunlight develop this deficiency.
The increased level of melanin content in the skin decreases the production of vitamin D in the skin. So people who are dark-skinned are at high risk of developing vitamin D deficiency
The level of calcium and phosphate in the body gets depleted as a result of the deficiency of vitamin D. This happens because vitamin D assists in the absorption of these minerals in the intestine. Hence, deficiency of this vitamin results in unhealthy bones and causes rickets in children and osteomalacia in adults.
If you notice a delay in sitting, crawling and walking in children, it might be a symptom of rickets. Rickets and osteomalacia are names given for deformities in bone that leads to bow legs, difficulty in walking, soft and fragile bones, frequent fractures and weak muscles.
Babies who are only fed breast milk, have a greater risk of developing this disease. Children who are born deficient in vitamin D become prone to several chronic diseases like cancer, diabetes and rheumatoid arthritis.
The deficiency can also cause diabetics as vitamin D regulates the secretion of insulin by the pancreas. An obese person needs almost double the amount of vitamin D needed by a non-obese person because the fat stored in the body depletes it of the vitamin.
Adequate Intake (AI) levels, that have been established by the U.S. Institute of Medicine of the National Academy of Science, are 5mcg daily for all individuals under the age of 50 years, 10mcg for people between 50-70 years and 15 mcg for people over the age of 70 years.
Vitamin D supplementation heals rickets promptly. 4,000 IU of oral supplement of the vitamin should be administered daily for approximately a month. A doctor’s advice and monitoring is definitely needed. Children with a deficiency of vitamin D should be encouraged to play outside and should be given foods that are good sources of the vitamin, like cod liver oil, butter, and egg yolks. People who live further away from the equator need to be exposed for longer periods, to the sun, in order to generate sufficient amounts of vitamin D.