Throughout the COVID-19 pandemic, there has been a ton of mix messages about what we can do to protect ourselves from coronavirus. One area the government has taken some action on is vitamin D.
Vitamin D is also known as the sunshine vitamin, as we get a majority of our vitamin D from the sun. We can also obtain vitamin D from our diet; however, there are only a few food sources so going outside for some fresh air and sunshine during the spring and summer months is highly recommended! During lockdown, we couldn’t do this so the government is recommending supplements.
Why do we need vitamin D I hear you ask? Vitamin D is vital for maintaining bone and muscle health. It’s so important that even if you are consuming a diet rich in calcium, if you do not have enough vitamin D, then there is poor absorption of calcium in your bones. There has also been some evidence that vitamin D is linked with healthy immune function; so much so that vitamin D deficiency is associated with respiratory infections in children.
Coronavirus and Vitamin D
Some of these concerns regarding coronavirus risk and vitamin D status were sparked from a p
ublication from the School of Medicine, and the Irish Longitudinal Study on Ageing (TILDA) and Pugach et al. (2020). Both studies concluded that there was an association between high rates of coronavirus and low vitamin D status. For instance, countries such as Spain and Northern Italy have had high numbers of coronavirus cases and vitamin D deficiency. Whereas countries such as Norway and Finland had lower levels of coronavirus infection and less vitamin D deficiency. Considering vitamin D deficiencies are associated with respiratory infections in children and the correlation between COVID and vitamin D deficiency, it was hypothesised that vitamin D may be involved in the body’s response to fighting the coronavirus disease.
However, this is just an association, so it doesn’t prove a cause and effect. There are multiple other factors that need to be taken into account; an ageing population, underlying health conditions and ethnicity for example. A 2016 SACN report suggested that there was a lack of evidence to support the notion that vitamin D supplementation reduces respiratory infection risk in adults.
More specifically to coronavirus, a rapid review has been published by NICE whcih looked at 5 studies, and found th
at once variables such as co-morbidities, ethnicity and BMI were considered, there was no significant relationship between vitamin D status and coronavirus risk.
There is currently no evidence to say the Vitamin D supplementation can help in the prevention or treatment of COVID infections!
Government guidelines suggest that a vitamin D supplement of 10μg/d (which may also been written as 10mcg/day
or 400IU/day) should be taken during the months between autumn and winter for general bone and muscle health. If you belong to one of the at-risk groups mentioned below, then supplementation may be particularly useful.
- You live where the air is polluted
- You spend little time outside, especially during the summer months or due to COVID shielding or self-isolation
- You live in the North as exposure to sunlight is reduced
- Your skin is mostly covered up
- when out and about
- You have a darker skin tone
- You are over the age of 65
- Pregnant and breastfeeding women
- You are an adolescent or younger
It may be tempting to take more than 10μg/d of vitamin D a day, may be potentially harmful in the long term. For instance, long term consumption of 10,000 IU/day is linked with increased vitamin D toxicity risk. If you wish to get any personalised advice about whether you need to take a vitamin D supplement, contact your GP or a registered dietitian or nutritionist (look for RD, RNutr or ANutr in their names).