Vitamin D is the vitamin of long life! This vitamin, in fact, not only protects bones, muscles and the immune system but, as emerges from a very recent scientific study, ensures health and longevity, while its deficiency increases the risk of chronic diseases. The study was published in the Annals of Internal Medicine by an Australian team from the University of South Australia (Sutherland et al, Ann Intern Med, 2022).
Vitamin D, function and causes of its deficiency
Vitamin D is a vitamin that performs various functions within the body. First of all, it promotes the absorption of calcium and its deposition in the bones, thus ensuring strong and robust bones and reducing the risk of fractures, rickets in children and osteoporosis in adults. Not only that, vitamin D preserves muscle function and counteracts weakness, modulates the immune system, reducing the risk of infections and autoimmune diseases. It also appears that vitamin D can help prevent or treat fibroids of the uterus by reducing their growth if they are already present (Brakta et al, Fertil Steril, 2015). The main source of vitamin D is the sun, followed by certain foods such as mushrooms, oily fish or eggs. Therefore, vitamin D is a vitamin whose presence is undoubtedly abundant. Despite this, however, it is not uncommon to have a vitamin D deficiency, indeed, according to estimates, 50% of the world population does not have sufficient vitamin D levels. Just think of those who stay indoors a lot, those who follow a not very varied diet, those who suffer from intestinal inflammation that do not allow proper absorption of the vitamin contained in ingested foods, or the elderly, whose skin is no longer so efficient at synthesizing vitamin D. The problem is that a vitamin D deficiency, especially when it is significant, not only increases frailty, weakness and propensity for infections, but it seems that it is going to reduce the duration of life. But let's understand better.
Vitamin D deficiency increases the risk of premature death
Australian scientists relied on data from 307,601 adults who participated in the large UK Biobank study and followed for 14 years. The researchers resorted to a particular technique, called Mendelian randomization, whereby genetic variations are used to look for causal relationships between modifiable risk factors, such as in our case vitamin D deficiency, and health conditions. In this way it is possible to evaluate how these modifiable factors can impact on the risk of disease and death. Well, what emerged is that vitamin D determines life expectancy and the risk of disease. In particular, the more serious the vitamin D deficiency is, the greater the risk of being diagnosed with diseases capable of shortening the life span. But it was also observed that, even in those who at the beginning of the study had a severe deficiency of vitamin D, the increase over the years of this vitamin has then made it possible to reduce the risk of disease and premature death.
Vitamin D, sources and warnings
The study allows us to understand how important it is to prevent, or treat, the deficiency of vitamin D. First of all, the advice is to expose yourself to the sun regularly, but avoiding the central hours of the day and without excess, in order to protect the skin from the risk of cellular degeneration. Then, it is important to include in your diet foods that are a source of vitamin D, such as some fish, such as sardines, salmon, trout and tuna, eggs, fortified milk and vegetable drinks to which vitamin D has been added, and fortified cereals. Mushrooms, such as shiitake, champignons, chanterelles or porcini, are also a source of vitamin D. However, it is the exposure to sunlight that increases the content of this vitamin in mushrooms. Therefore, outdoor mushrooms have higher amounts of vitamin D than those cultivated in dark conditions. However, recent research has shown that exposing cultivated mushrooms to ultraviolet light significantly increases their vitamin D content (Koyyalamudi et al, J Agric Food Chem, 2009). Then there are supplements, to be taken only in case of severe deficiency or increased need for vitamin D and always under medical supervision.