With the whole world in the grip of a pandemic, with no available vaccine, people are desperate to find something that will protect them and their loved ones. Right now it’s a bit like the Black plague when people would use crazy ‘cures’ like rubbing onions, herbs or a chopped up snake (if they could find one) on the boils or cutting up a pigeon and rubbing it over an infected body. Drinking vinegar, eating crushed minerals, arsenic, mercury or even ten-year-old treacle! Sitting close to a fire or in a sewer to drive out the fever or fumigating the house with herbs to purify the air. we’ve had people do crazy thing like ingesting bleach! Wearing a mask has almost become a fashion statement. It’s probably a great time to buy shares in a hand sanitizer producer…. or Amazon! Still, there’s not much hard evidence out there about what will ensure you don’t catch the virus. Still, taking precaution like wearing your mask in public, keeping your distance, washing your hand regularly all helps.
There has been a lot in the media about the benefits of vitamin D, and how it could possibly help prevent you from becoming very ill from Covid. Or even from getting it at all. So, is there any truth to this? First let’s look at what the functions of vitamin D are, and the main sources.
Vitamin D is a fat-soluble vitamin that occurs naturally in only a few foods but can be used to fortify many types of food. The main sources of vitamin D are;
- Oily fish (mackerel, salmon, herring)
- Liver
- Red meat
- Egg yolks
- Fortified foods such as cereals, other dairy products.
- Supplements
- It’s produced in the skin through UV radiation from the sun
The most well-known function of vitamin D is that it helps with the absorption of Calcium in the gut. This helps maintain normal levels of Calcium and Phosphate concentrations for strong bones and teeth. It also prevents Hypocalcaemia; this is when there are low blood calcium levels and the muscles begin to involuntarily cramp and spasm. This is very painful, (from personal experience).
Research has also shown that vitamin D plays a key role in immunity. Many studies have shown it can help reduce the risk of getting influenza, but there are also studies that contradict this. Vitamin D improves cellular immunity, partly by controlling inflammation provoked by the innate immune system. The innate immune system produces pro-inflammatory and anti-inflammatory cytokines in reaction to viral and bacterial infections, such as Covid-19.
You mainly hear about how the elderly and medically vulnerable (i.e. people with chronic illness), seem to catch the virus easier and are more likely to become extremely ill or even die from it. Studies have shown that people with chronic illnesses tend to have lower serum vitamin D concentrations than healthy people. Now it hasn’t been proven that the reason this virus seems to affect this category of people worse is linked with vitamin D concentrations, it’s merely an observation at present.
The elderly is another group who have been hit hard by Covid. It has been shown that serum concentrations of vitamin D do tend to decrease with age, so maybe that is the reason? Also, many elderly people who are unable to get much sunlight due to being immobile, hospitalized or maybe in a nursing home would tend to have lower vitamin D levels than someone able to go outside and get some sun.
Vitamin D deficiency is a very common problem in Ireland. A level of less than 50mmol/L is classified as deficient. Vitamin D deficiency has been linked to an increased risk in acquiring acute respiratory infections and community acquired pneumonia. Supplements have been shown to reduce this risk, and it has been recommended that in Ireland everyone should be taking a vitamin
D supplement, especially for the autumn and winter months when not only is there less sunlight, but the UV rays are not as efficient for producing vitamin D. This could be why influenza is most common during the winter months. A study carried out in 2019 with 21,000 subjects showed that those deficient in vitamin D had a 64% increased risk of getting community acquired pneumonia.
Another sign that points to vitamin D’s effectiveness at protecting against Covid is that countries that are more ‘northernly’ seem to be hit hard by the virus. There is a 4.4% increase in deaths from Covid for each degree latitude north of 28’, this link remained even after it was adjusted for the age of the population.
The EU recommendations for how much vitamin D a person should consume per day is illustrated in table 1 below;
Table 1: EFSA recommendation for vitamin D intake for males and females
| Age | Minimum | Maximum | |
| Infants | 7-11 months | 10µg/day | 35µg/day |
| Children | 1-10 years | 15 µg/day | 50 µg/day |
| Teenagers | 11-17 years | 15 µg/day | 100 µg/day |
| Adults | ≥18 years | 15 µg/day | 100 µg/day |
| Pregnant | – | 15 µg/day | 100 µg/day |
| Lactating | – | 15 µg/day | 100 µg/day |
Obviously, the best way to get your recommended amount of vitamin D is through food and getting enough sunlight without harming your skin but taking a daily supplement will help ensure you are getting enough. You can get vitamin D supplements over the counter in your chemist, or at your local health food shop. Just be careful to read the dosage instructions and follow them. Vitamin D toxicity is very rare but can be very severe. You can only get vitamin D toxicity from overuse of supplements, and I mean taking over 1000µg/day for several weeks. If you are on other medications or have any medical conditions, it’s a good idea to consult your doctor before starting any kind of supplements.
So, in conclusion, do I think Vitamin D supplementation is a potential treatment, prevention or cure for Covid-19? The answer is, I don’t know! The virus is still so new, and there have only been a few trials done on vitamin D and Covid. What I do know is that there is enough evidence showing that good vitamin D levels has many health benefits, including strengthening your immune system against respiratory infections. I think people should try to increase their intake of vitamin D, especially over the winter months. But I don’t recommend discarding all other protective measures such as wearing a mask, washing your hands and keeping your distance from others, Making yourself healthier in general by eating healthier, exercising, looking after your mental health will help keep your immune system strong and ready to fight if needs be!
These are the main articles I looked at to write this post
https://onlinelibrary.wiley.com/doi/epdf/10.1111/joim.13158
http://www.indymedia.ie/attachments/may2020/covid-19_vit_d_irish_med_j_mccartney.pdf
https://www.mdpi.com/2072-6643/12/4/988
https://www.efsa.europa.eu/en/interactive-pages/drvs
Thanks for reading, and I hope this post helps!
Sorcha x
