The sun has always been the most important source of energy for all living beings in the world. The sun makes life possible.
Your body needs sunlight to stay healthy. Sunlight is the major source of vitamin D for human beings.
Vitamin D is a kind of fat-soluble vitamin needed by all living beings. This vitamin is also known as calciferol. Though it is present in a few food sources like fatty fish (salmon, tuna, sardines), mushrooms, and egg yolks, a majority of vitamin D is obtained from sunlight naturally.
Depending on their chemical composition, there are 5 different types of vitamin D available.
Out of these, Vitamin D2 and D3 are the major ones usually discussed.
Rickets is a condition that causes soft bones in children. The telltale signs of rickets are bowed legs, an abnormally large forehead, a curved spine, and stunted growth.
There are mentions of children born with deformed bones as early as in the first and second centuries AD. Though rickets was not identified as a specific medical condition until 1645, instances of children born with bone deformities were quite common.
Until the early 20th century, the reason and cure for rickets remained a mystery. Parents with newborns had no idea whether their child would grow up healthy or end up with bone deformities and stunted growth.
In 1914, Elmer McCollum, an American biochemist, identified that a certain additive in cod liver oil helped prevent rickets. He assumed it was vitamin A.
In 1922, he realized that cod liver oil without vitamin A, also prevented rickets. This led to the identification of a new 4th vitamin in history and this was named vitamin D. At that time, people did not realize sunlight could produce vitamin D.
That knowledge was brought forth by another American physician Alfred Hess who concluded “Light equals vitamin D”
The skin consists of two layers - the outermost layer, epidermis and the inner layer, dermis. The epidermis is made up of 5 layers. Vitamin D is produced using sunlight by the two innermost layers of the epidermis.
7-Dehydrocholesterol, also known as 7-DHC, is a chemical compound that is made in the skin in large quantities. 7-DHC reacts with the ultraviolet (UV) rays from the sun and is converted into vitamin D.
This process happens in the arms, legs, and face. The produced vitamin D is then carried in the blood to the liver. Here it is converted into a pre-hormone (a chemical substance produced by glands that is later converted into hormones) known as calcifediol.
Calcifediol is then converted into calcitriol in the kidneys, which is the vitamin D form actually used by the body. From here, calcitriol is sent out for circulation.
More and more doctors and scientists globally are encouraging people to increase their vitamin D intake to prevent the severity of the COVID-19 infection.
With the vaccine for coronavirus still not approved or available, people are looking towards alternate solutions to boost their immunity. Vitamin D has emerged as a powerful nutrient to keep away infections.
There are a few notable studies conducted around the world that link vitamin D deficiency to an increased risk of developing COVID-19. Some studies say people living in areas that receive lesser amounts of sunlight see higher coronavirus deaths.
Few other studies point to the fact that people with vitamin D deficiency seem to have worse symptoms when they test positive for the infection.
While there could be links between vitamin D consumption and the effects of the coronavirus, as of now, there is no solid proof that the vitamin can completely prevent or cure the infection.
The National Institutes of Health has also given out a statement stating that there is no evidence vitamin D can treat COVID-19.
However, making sure you get your recommended dose of vitamin D will definitely keep your immune system healthy during this pandemic.
According to the Food and Nutrition Board, here are the daily recommended intake values of vitamin D.
Excess quantities of vitamin D are unsafe. When you consume excess vitamin D, the calcium levels in the body increase too. This condition is called hypercalcemia. Hypercalcemia can result in the below conditions:
Vitamin D toxicity can also cause hypercalciuria (excess calcium in the urine). Extreme cases of vitamin D toxicity can lead to renal failure, irregular heartbeat, and even death.
Overexposure to the sun does not usually cause vitamin D toxicity because the skin learns to regulate the amount of vitamin D it produces. However, excessive use of tanning beds and excess consumption of vitamin D supplements can both cause vitamin D toxicity.
When your vitamin D levels are low because of unhealthy eating habits and less/no exposure to sunlight, you can get vitamin D deficient with time.
In children, vitamin D deficiency is reflected as rickets disease. Children can also suffer from developmental delays and dental problems early on. In adults, this can cause a condition called osteomalacia. Osteomalacia causes soft and weak bones. Adults also develop dental issues because of vitamin D deficiency.
There are two genes that seem to affect vitamin D concentrations in the body. Variations in these genes can cause increased/decreased needs for vitamin D.
GC gene - The GC gene is responsible for making the Vitamin D binding protein (VDBP) that helps in transporting vitamin D. One particular variant (type) of the GC gene is known to cause vitamin D deficiency.
CYP27B1 gene - The CYP27B1 gene is responsible for making vitamin D active and available for use by the cells in the body. One particular type of this gene can cause lowered vitamin D levels in the body.
Vitamin D is a hot topic these days. We get it from the sun, fortified milk, butter, ghee, soybeans, soy milk, cheese, eggs and certain types of fish and mushrooms. It’s usually credited with promoting bone strength and overall health. And vitamin D deficiency has been linked to many chronic diseases, including, but not limited to, infectious diseases, autoimmune diseases, cardiovascular diseases, diabetes and cancer.
A recent study revealed that a whopping 70% of the Indians suffer from vitamin D deficiency. This study further adds that sunlight exposure is not a tenable solution to obtain vitamin D sufficiency among Indians, as darker skin has high melanin content and produces a significantly lesser amount of vitamin D when compared with individuals with fairer skin. Indian skin tone requires daily sunlight exposure of at least 45 minutes to produce sufficient amounts of vitamin D.
You may also need more vitamin D depending on the genes that you carry. Variations in two genes, GC and VDR, are responsible for lower vitamin D levels. The GC gene produces the main transporter of vitamin D in circulation while VDR gene produces vitamin D receptor which allows the body to respond appropriately to vitamin D. Compared to others, people carrying one type of GC and one type of VDR need to ensure they have adequate sun exposure or dietary intake of vitamin D to avoid deficiency.
Various nutritional factors attributing to high prevalence of vitamin D deficiency in India are:
|Most Indians are vegetarians and most of the foods rich in vitamin D are of animal origin. Indian diets are low in calcium and high in phytate. High prevalence of lactose intolerance is a major factor for reduced intake of calcium and vitamin D. Intake of caffeine from coffee and tea is high in India.|
Factors such as age (old age), body weight (people with a body mass index of 30 or greater), problems of the digestive tract like Crohn’s disease and cystic fibrosis, kidney problems results in low blood levels of vitamin D.
The National Institute of Nutrition recommends 200 units, 5 mcg of vitamin D everyday. The following are the recommendations from the vitamin D council:
|It is essential to maintain healthy levels by including fatty fish such as salmon, mackerel, herring, tuna, fish oils, egg yolks, fortified milk and other fortified foods such as cereals etc. Vitamin D supplements could be a good alternative. Many forms of vitamin D exist, with vitamin D3 the most effectively used in the body. Get adequate sunlight exposure: The amount of vitamin D you get from exposing your bare skin to the sun depends on the time of the day, where you live, the color of your skin and the amount of skin you expose.|
Want to know what type of VDR and GC gene you have, Xcode’s nutrigenetics test can tell you what versions of the VDR & GC gene you have in your DNA. You can also learn about how your genes may influence other traits, including your risk for certain diseases. You can write to us at firstname.lastname@example.org.