Vitamin D is a steroid hormone that has been associated primarily with bone growth and calcium deposition for years. Over the last ten years, its special role in the metabolism of the skin, brain, T and B lymphocytes, pancreas and cardiovascular system has become clearer. With vitamin D receptors on almost the entire surface of the intestine, it is one of the key elements of the immune response.
Vitamin D deficiency
It is estimated that about 50 percent of Europe’s population is deficient in this vitamin, of which 13 percent is severely deficient. Lifestyle changes as well as moving from the countryside to polluted cities are the main culprits for such a high deficiency of this vitamin.
Vitamin D is unique in that our body only produces it by exposing the skin to the sun. It exists in the form of Vitamin D3 which our bodies produce and Vitamin D2 which is found in the food we eat.
It takes between 1,000 and 1,500 hours of skin sun exposure annually with a minimum dose of redness to produce an adequate amount of vitamin D. Vitamin D formed in this way lasts 2 times longer in circulation than vitamin D which is ingested through food or supplements. Exposure of the body to sunlight until a minimum amount of mild redness appears on the skin allows the synthesis of vitamin D equal to the intake of 10,000 to 25,000 units of vitamin D.
Benefits of adequate amount of vitamin D
Benefits of adequate amount of vitamin D are numerous and the following are the most important:
- It reduces the possibility of developing cancer because it prevents the rapid proliferation of cells as well as the formation of new blood vessels.
- It provides heart muscle health through kidney metabolism as well as through receptors on blood vessels.
- It reduces blood pressure.
- Obesity is associated with vitamin D deficiency.
- The risk of type 2 diabetes is reduced by taking 700 IU of vitamin D per day.
- Depressed people who received 20 to 40 thousand units a week had better results in overcoming depression.
- High levels of vitamin D reduce the risk of multiple sclerosis by 62%.
Vitamin D synthesis in humans
Several factors that affect the synthesis of vitamin D should be taken into account.
- • Wearing SPF 30 reduces vitamin D synthesis by 95%.
- • People with darker complexion have a more intense defense against UVB radiation and thus decreased vitamin D synthesis. They need 3 to 5 times longer sun exposure in order to produce the same amount of vitamin D as fair-skinned people.
- • Obese people deposit vitamin D in adipose tissue, so they need a much larger amount for adequate blood circulation.
- • Ageing of the skin reduces the ability to synthetize vitamin D.