Numerous scientific papers have been published recently suggesting that high doses of vitamin D (more than 10 micrograms or 4000 IU per day) could reduce the risk of getting Covid-19 or be used to treat the disease.
Let's look at this in more detail.
So what is Vitamin D?
Vitamin D is a hormone that helps regulate the amount of calcium and phosphate in our body.
Together, they work to keep our bones, teeth and muscles healthy.
Our main source of vitamin D comes from exposure to sunlight.
The NHS (UK) says "most people can make enough vitamin D from being out in the sun daily for short periods with their forearms, hands or lower legs uncovered and without sunscreen from late March to early April to the end of September especially from 11am to 3pm".
However, being outdoors regularly for extended periods of time especially without any sunscreen can increase the likelihood of skin cancer.
So where can I get vitamin D from if not from sunlight?
Vitamin D occurs naturally in fatty fish such as:
Salmon
Sardines
Trout
Mackerel
Herring
Eel
It also occurs naturally in the following foods:
Egg yolk
Red meats
Liver
Milk
Margarine
Breakfast cereals
Fruit juices that are fortified with vitamin D
Cod liver oil
Mega-dosing - harmful or not?
So, if vitamin D is a super vitamin has so many health benefits and it potentially protects us from Covid-19, I should take as much vitamin D as possible right?
No.
Excess amounts of vitamin D resulting from taking mega-doses may be harmful.
Vitamin D is stored in fat cells and we only have a fixed amount of fat cells.
Any excess will just remain in the blood since vitamin D is not soluble and can't be excreted in the urine.
Is vitamin D really a treatment for Covid-19?
Unfortunately, there is not enough evidence to prove that vitamin D is a treatment for Covid-19.
In a recent paper published in the British Medical Journal, Nutrition, Prevention and Health, the authors concluded that "Although there is some evidence that low vitamin D is associated with acute respiratory tract infections, there is currently insufficient evidence for vitamin D as a treatment for Covid19 and over-supplementing must be avoided as it could be harmful."
Takeaway
Eat a balanced diet, including foods that contain vitamin D.
Go out and enjoy safe sunlight exposure, because why not? It'll also help boost your levels of vitamin D.
Supplement with 10 micrograms of Vitamin D if you are self isolating and/if you have limited exposure to sunlight.