Vitamin D Keeps Viruses Away During Winter, Research Finds
There has been much debate in the medical world lately regarding the role of vitamin D in the body. It seems that vitamin D plays a role not only in bone growth, but also an important role in immunity and antitumoral protection. According to a study published in the Journal of leukocytic Biology, vitamin D seems to also protect against viral infections during winter.
Vitamin D3, or cholecalciferol, is produced in the skin from 7 dehydrocholesterol under ultraviolet rays. So, during in winter, vitamin D synthesis in the skin is low. 7 dehydrocholesterol is then transformed into cholecalciferol by a non-enzymatic reaction, under the influence of UVB. Colecalciferol is then converted in the liver in 25 hydroxy cholecalciferol (circulating vitamin D), with poor biological activity. From the liver, it is then transported to the kidneys where 25 hydroxy cholecalciferol is converted into 1, 25 dihydroxy cholecalciferol. The latter has the highest biological activity and is considered a hormone with a role in regulating calcium metabolism.
Vitamin D has several roles in the body. In the intestine increases calcium absorption and phosphate by stimulating the synthesis of transport proteins. In the bone, it maintains calcium-phosphate balance and promotes bone formation by stimulating osteoclast bone resorption. It is a well-known fact vitamin D deficit causes osteoporosis or osteomalacia. Moreover, it has recently been discussed the role of vitamin D in immunity and the possible role of this vitamin in cancer treatment. Furthermore, vitamin D deficiency is considered a risk factor for tuberculosis.
Victor Manuel Martinez-Taboada, MD, a researcher involved in the work from the Division of Rheumatology at the Hospital Universitario notes that vitamin D is extremely important for human health. He also added that supplements vitamin D can be useful when conventional treatments fail.
According to the study published in the Journal of leukocytic Biology, supplements of vitamin D protect against viral infections during winter. The researchers measured blood levels of vitamin D in individuals that have divided into 3 categories according to age. What they found was that the vitamin decreases with aging. They also have observed that low levels of vitamin D is correlated with low levels of TLR, toll like receptor, especially TLR 7, a molecule found on the surface of lymphocytes and leukocytes. These molecules have a role in antiviral protection. Therefore, vitamin D should be supplemented during winter. However, further studies must be performed in order to check whether vitamin D deficiency is indeed associated with low immunity during the winter months.