Vitamin D: a place in the sun

Frequent colds, fatigue, insomnia… A common reaction to inclement weather? Perhaps the point is something else – a deficiency of vitamin D. It is necessary to maintain our immunity, and in addition, it affects the state of the nervous system, heart function and blood clotting. Recent studies show that the prevention of a number of cancers is also directly related to the content of this vitamin in the body*. In fact, this substance is called a vitamin only by tradition: it has a hormonal nature. In our body, it is mainly synthesized under the influence of ultraviolet rays. Or (in significantly smaller quantities) comes to us with food. In them, vitamin D is in the so-called inactive form, which our body then “activates” under the influence of the same sunlight, turning it into the hormone calcitriol, a regulator of calcium and phosphorus metabolism. It is he who is responsible for the healthy state of bone tissue, protects children from rickets, and older people from osteoporosis.

Outside…

The surest way to replenish your vitamin D stores is to get out in the sun. In summer, a 20-minute walk on a fine day in open clothes will be enough. At the same time, it is worth observing the measure in tanning: very tanned skin begins to transmit much less ultraviolet radiation than it is necessary for the body to produce a “solar” vitamin. The cause of vitamin D deficiency can be prolonged cloudy weather, which is typical of our latitudes. In summer and autumn, a moderate deficiency of vitamin D is observed in only 13% of adults, but in the winter-spring period this figure rises to 36% **.

… And on a plate

Most often, vitamin D can be found in animal products, such as butter and egg yolk … that is, in those foods that many have recently changed their attitude to due to interest in healthy eating . There is a lot of vitamin D in the liver, which not everyone loves, and in sea fish, which we do not eat enough. Vitamin D preparations can also become a source of vitamin D. Which of us misses it the most? The three main risk groups are children, pregnant women, and the elderly (who, due to their age, have slower vitamin D synthesis). But not only them. “The reason for the lack of vitamin D can be diseases of the liver and kidneys,” explains pharmacologist Boris Romanov, head of the Department of Pharmacology of the Faculty of Pharmacy of the Medical Academy. Sechenov. “It is in these organs that the original form of the vitamin is converted into the hormone calcitriol.” To determine the deficiency of vitamin D in the body, a blood serum test is performed. It can be prescribed by the attending physician and, in case of hypovitaminosis, prescribe the necessary drugs.

¹ In a group of women who, during a four-year clinical experiment by American scientists who took vitamin D, the number of cases of breast and rectal cancer was 60% less than in the control group. See: J. Lappe “Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial”. American Journal of Clinical Nutrition, 2007, vol. 85.

² H. Li, M. Stampfer, J. Hollis, L. Mucci et al. «A prospective study of plasma vitamin D metabolites, vitamin D receptor polymorphisms, and prostate cancer». PLoS Medicine, 2007, vol. 4.