1. Sunlight
Under ultraviolet vitamin D produced in the skin from which it is then absorbed into the body. Of course, when the streets full of smog, ultraviolet worse reaches the earth's surface, therefore, the body begins to produce less vitamin D. By the way, if a person is sunburned, the production of vitamin D through the skin stops.
2. Food
Vitamin D is also supplied in the diet. But since this vitamin is fat-soluble, to assimilate fats in the intestine are required. In addition to the traditional fish oil, a good source of vitamin D is a saltwater fish, milk and dairy products, egg yolk, mushrooms, parsley and sunflower seeds.
Dose of vitamin D is measured in international units (IU). Daily rate of vitamin D for adults is 400-1000 IU. The daily dose exceeding 2,500 IU takes a long time, toxicity, and dose exceeding 5,000 IU can even cause unpleasant effects - very thirsty, itchy skin, eye inflammation, diarrhea or vomiting, sudden urge to urinate, abnormal calcium deposits in the vascular and walls of internal organs.
How useful vitamin D?
It is required for proper assimilation of trace elements necessary to strengthen the bone and dental tissue - phosphorus and calcium. In addition, vitamin D is essential for the absorption of vitamin A for preventing colds vitamin D also is not more than (preferably in combination with ascorbic acid).
What happens when a lack of vitamin D?
Increases the likelihood of developing rickets and osteoporosis, tooth decay, softening and skeletal deformities. In addition, some modern scholars believe that long-term vitamin D deficiency can cause cancer.
That destroys vitamin D?
Chemically synthesized mineral oil is sometimes used in cooking (salad dressings), and sometimes in medicine (laxative). This oil dissolves many essential vitamins, including D, taking them out of the human body. Therefore, as far as possible from the mineral oil should be avoided.
Who need high doses of vitamin D?
Residents of large cities should increase the intake of vitamin D because of the smog. The same should do the people who work the night shift, and generally anyone who is little in the sun, being mostly indoors. Dark-skinned people living in the Nordic countries, is also worth to eat more vitamin D from food.