What is vitamin D?
Vitamin D is a nutrient that plays many important roles in the human body. There are two major types of vitamin D, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Our body can get vitamin D from sunlight, natural food and dietary supplements.
When we are exposed to sunlight, type B UV (UVB) acts with 7-dehydrocholesterol, a form of cholesterol in the skin, and produces vitamin D3 according to Fact Sheet for Health Professionals’ vitamin D brief, published in the National Institute of Health (NIH) last October.
Since vitamin D3 is generated naturally from exposure to the sun, people call vitamin D the “sunshine” vitamin. Our diets are another source of vitamin D (both D2 and D3). NIH states in its fact sheet that the best foods providing vitamin D include fatty fish such as trout, salmon, tuna, and mackerel. Since there are limited foods that can provide vitamin D, taking vitamin D supplements properly and exposing yourself to sun is essential. Some people with certain medical conditions, such as kidney problems, cannot safely take vitamin D.
If you have any questions about your level of vitamin D, it is wise to consult your doctor.
How important is vitamin D to our health?
Vitamin D plays many important roles in the body. A deficiency can lead to numerous health problems. Vitamin D deficiency can cause rickets in children and osteoporosis in adults. Its main function is to help the body absorb calcium, which is necessary to maintain strong bones. Without vitamin D, the bones in the body become soft, thin, and brittle due to an insufficient calcium supply. Vitamin D is also necessary for the proper functioning of your immune system, your body’s first line of defence against infection and disease. This vitamin plays a critical role in promoting immune response.
Research published in the British Medical Journal (BMJ) in August 2011 stated that deficiency in vitamin D is associated with increased autoimmunity and an increased susceptibility to infection. An autoimmune disease causes your immune system to mistakenly attack your body. Normally, the immune system can tell the difference between foreign cells and your own cells. With an autoimmune disease, the immune system mistakes parts of your body, such as joints or skin, as foreign. As immune cells in autoimmune diseases are responsive to the ameliorative effects of vitamin D, the benefits of supplementing vitamin D-deficient individuals with an autoimmune disease may extend beyond the effects on bone and calcium homeostasis.
According to the World Health Organization (WHO), vitamin D deficiency is linked to respiratory infections such as pneumonia, tuberculosis and bronchiolitis. Pneumonia is the leading cause of death in children worldwide.
Can vitamin D prevent Covid-19?
Although there is still no definitive answer to this question, scientists are conducting studies on vitamin D to find out.
A study published in The Journal of the American Medical Association in September 2020 looked at 489 patients who had their vitamin D level measured in 2019 and COVID-19 testing. Researchers found that the relative risk of testing positive for COVID-19 was 1.77 times greater for patients with deficient vitamin D status compared with those with sufficient level.
In another study published in the Journal of Internal Medicine in July 2020, researchers found a connection between more northerly countries in the Northern Hemisphere and a relatively high COVID‐19 mortality. In countries such as the United States, Canada and Britain, people generally get less vitamin D from the sun throughout the year.
At the same time, scientists think that climates with high temperatures, humidity and ultraviolet rays may also affect the virus’ survival. As such, they do not really know how vitamin D affects COVID-19.
Aside from COVID-19, it is important to get the proper intake of the vitamin. This includes eating the appropriate foods listed earlier. In addition, doctors encourage sunbathing. The Harvard Medical School website notes wearing sunscreen will not detract seriously from producing vitamin D.
According to the National Health Service UK (NHS), it is important for those who spend more time staying indoors to take supplements. In addition, Health Canada recommends that people over the age of 50 take a daily the supplement of 400 International Units (IU) (equivalent to 10 micrograms).
Currently, the WHO says there is not enough evidence to prove that taking vitamin D can prevent COVID-19 or help treat the disease. But many scientists believe that this nutrient provides health benefits that keep people in good condition. Consult with your doctor if you are considering increasing your intake.
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