Vitamin D deficiency bad for the bones

Lack of sun leads to bone damage - beach vacation as a protection against vitamin D deficiency?

07/11/2013

Sufficient sun exposure is not only important for the mind, but also for the bone structure. Because the vitamin D required for bone formation can be produced by the organism only when the skin contacts the sunlight to the required extent. Scientists at the University Medical Center Hamburg-Eppendorf (UKE) have now re-examined the effects of vitamin D deficiency on the bones and found that this not only affects bone mineral density, but also interferes with mineralization and causes the bones to age prematurely , This contributes significantly to the increased susceptibility to bone fractures. The researchers published their findings around lead author Björn Busse from the Institute for Osteology and Biomechanics at UKE in the journal „Science Translational Medicine“.

Vitamin D is not a vitamin in the conventional sense, but actually a hormone. The intake can be made only to a limited extent through the diet. However, the organism forms vitamin D upon contact of the skin with sunlight. However, if only little sunlight reaches the skin, as was the case for example in the extremely sun-poor winter of the past, a vitamin D deficiency quickly sets in, which has a highly detrimental effect on the ongoing process of bone formation or bone regeneration. So far, vitamin D deficiency has been associated with a reduction in bone density, but researchers in Hamburg now conclude that it also causes premature aging of the bone. The increased fracture risk is due to the interaction of the two factors.

Increased risk of bone fractures
The researchers at the University Medical Center Hamburg-Eppendorf (UKE), in collaboration with researchers from the Institute of Materials Science at the University of California, Berkeley, investigated the bones of 30 deceased patients using complex procedures for their composition, density and susceptibility to fractures. According to the researchers, more than half of the deceased suffered from vitamin D deficiency. A study of the fracture mechanics of bones by means of so-called micro-computed tomography revealed that the vitamin D deficiency „both the formation and the propagation of fractures increased“, report buses and colleagues.

Disturbed mineralization of the bone in vitamin D deficiency
The scientists found that the characteristic increase in soft bone tissue (osteoid) covered areas in vitamin D deficiency interferes with the mineralization of the remaining bone tissue. The analysis of bone mineral density also showed that the soft bone tissue has a higher proportion „of mature collagen and mineral constituents characteristic of aged tissue“, so buses and colleagues continue. Thus, not only does bone density decrease in vitamin D deficiency, but the bones also show exemplary aging due to the mineralization disorder, thereby further increasing the risk of bone fractures.

Sufficient sunlight is needed for vitamin D formation
The important function of vitamin D in bone formation is also shown by the clinical picture of osteomalacia (rickets in children), which can be associated with considerable bone pain and severe skeletal system impairment. In the prevention of osteoporosis, the sufficient intake of vitamin D is also attributed a significant importance. Although small amounts of vitamin D can also be absorbed through the diet, a deficiency can hardly be avoided without enough contact with sunlight. Sufficient sun is not always available in our latitudes. According to the scientists of the UKE, it is only south of the 37th latitude that sufficient sunlight is available throughout the year for vitamin D production. In Germany, however, the body sometimes has difficulty in the few hours of sunshine in winter to form vitamin D to the extent necessary. The result is that many people in this country suffer from a latent vitamin D deficiency, which, according to the findings of the Hamburg researchers, also weakens the bones and increases the risk of fracture. (Fp)