Lack of sun leads to bone damage - beach vacation as protection against vitamin D deficiency?
Adequate sun exposure is not only important for the mind, but also for the bone structure. Because the vitamin D required for bone formation can only be produced to the required extent by the organism when the skin comes into contact with sunlight. In a current study, scientists from the University Medical Center Hamburg-Eppendorf (UKE) have again examined the effects of a vitamin D deficiency on the bones and found that this not only affects the bone density, but also interferes with the mineralization and causes the bones to age prematurely . This contributes significantly to the increased susceptibility to broken bones. The researchers, led by Björn Busse from the Institute for Osteology and Biomechanics at the UKE, published their results in the journal "Science Translational Medicine".
Vitamin D is not a vitamin in the traditional sense, but actually a hormone. It can only be ingested to a limited extent through food. However, the organism produces vitamin D when the skin comes into contact with sunlight. However, if only a little sunlight reaches the skin, as was the case, for example, in the extremely low-sun winter in the past, a vitamin D deficiency quickly arises, which has an extremely disadvantageous effect on the ongoing process of bone building or bone renewal. So far, he has been associated with a vitamin D deficiency mainly as a decrease in bone density, but the Hamburg researchers now come to the conclusion that it also causes premature bone aging. The increased risk of fractures is caused by the interaction of the two factors.
Increased risk of broken bones In the course of their study, the scientists at the University Medical Center Hamburg-Eppendorf (UKE) worked together with researchers from the Institute of Materials Science at the University of California at Berkeley to find the bones of 30 deceased using complex procedures to determine their composition, density and susceptibility examined for fractures. According to the researchers' analyzes, more than half of the deceased suffered from a vitamin D deficiency. An examination of the fracture mechanics of the bones using so-called micro-computed tomography showed that the vitamin D deficiency "increases both the occurrence and the spread of fractures," reports Busse and colleagues.
Impaired mineralization of the bone in vitamin D deficiency The scientists found that the characteristic increase in the areas covered with soft bone tissue (osteoid) in the case of vitamin D deficiency disrupts the mineralization of the remaining bone tissue. The analysis of the bone mineral density also showed that the soft bone tissue had a higher proportion "of mature collagen and mineral components, which are characteristic of aged tissue", Bussen and colleagues continue. Accordingly, not only does the bone density decrease with vitamin D deficiency, but the bones also show an ideal aging due to the mineralization disorder, which increases the risk of bone fractures.
Sufficient sunlight required for vitamin D formation The important function of vitamin D in bone formation can also be seen in the clinical picture of osteomalacia (rickets in children), which can be associated with considerable bone pain and severe impairments of the skeletal system. In the prevention of osteoporosis, sufficient intake of vitamin D is also considered to be of considerable importance. Although small amounts of vitamin D can also be absorbed through food, a deficiency can hardly be avoided without sufficient contact with sunlight. Sufficient sun is not always available in our latitudes. According to the scientists at the UKE, sufficient sunlight for vitamin D formation is only available all year round south of the 37th parallel. In Germany, however, the body sometimes has difficulty in producing the required amount of vitamin D during the few hours of sunshine in winter. The result is that many people in this country suffer from a latent vitamin D deficiency, which according to the Hamburg researchers' findings also weakens the bones and increases the risk of fracture. (fp)
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