Why should I take vitamin D supplements?

Lockdown and low vitamin D levels may add to people being more vulnerable to COVID-19 this winter. We will talk about vitamin D sources, supplements and the importance of taking vitamin D.

Why do we need vitamin D?

A recent report from the Academy of Medical Sciences recommend people to prepare this winter due to concerns about a second wave of COVID-19. Low vitamin D levels are common in the UK. Approximately one in five people have low levels of vitamin D. For example, during wintertime our bodies cannot make vitamin D from direct sunlight as it does not contain enough UVB radiation. Additionally, it is difficult to get enough vitamin D from the diet. As a result of this and the lockdown the government has recommended of a daily vitamin D supplement.

There is currently little evidence that shows Vitamin D can be used to treat or prevent COVID-19. However, research has shown that vitamin D supplementation can prevent acute respiratory tract infections and is important for bone and muscle health.  Vitamin D helps with calcium absorption and has a key role in keeping bones strong. Therefore, this helps to prevent future broken bones and it plays an important role in supporting the immune system.

What is vitamin D?

Vitamin D is a fat soluble vitamin. There are two types of vitamin D; vitamin D3 (colecalciferol) and vitamin D2 (ergocalciferol).  

You can make vitamin D3 from sunlight shining directly on your skin. Lichen and sheeps wool can be used to make vitamin D3 supplements. Whereas, vegan vitamin D2 supplements are derived from fungi and yeast. In the UK from March to September it is possible to get enough vitamin D from sunshine. However, not everyone can achieve this therefore vitamin D supplements are recommended. 

How much vitamin D do I need?

The current UK government advice is to take 10 micrograms of Vitamin D every day from age 1. Similarly, babies up to age 1 should take 8.5 to 10 micrograms a day. Due to the Coronavirus pandemic more people are spending time indoors and so do not spend enough time outdoors to get vitamin D from sunshine.  If you are vitamin D deficient or insufficient please seek advice from a doctor

flow chart showing vitamin D requirements for all age groups

The UK government recommends a daily supplement of 10 micrograms vitamin D throughout the year if you aren’t often outdoors – for example, if: 

  • Shielding, frail, housebound 
  • Self-isolating
  • Living in a care home
  • Usually wearing clothes that cover up most of your skin when outdoors
  • You have dark skin 

Food that contains vitamin D

The amount of vitamin D in foods can vary. Animal sources contain the most vitamin D. However, fortified foods have small amounts.

Foods such as oily fish e.g. baked salmon (15.5 micrograms per 140g portion) and tinned sardines (4.6g per 140g portion) contain a significant amount of vitamin D. Whereas, animal products such as chicken breast (0.2 micrograms per 100g portion) and roast pork (0.9 micrograms per 90g portion) contain less vitamin D.

Plant based sources of vitamin D such as ultra-violet light exposed mushrooms can vary. Research has shown that storage and cooking can affect the amount of vitamin D present. It can range from less than 1 microgram per 100g to as much as 10 micrograms per 100g. 

vitamin D food sources with food icons to show the different foods

There is a useful resource about vitamin D from the British Nutrition Foundation. It shows the amount of Vitamin D in certain portions of food and provides an example menu which will help you to achieve the daily 10 microgram vitamin D target.


The government has recommended Vitamin D supplements to ensure the population has sufficient vitamin D all year round. Vitamin D can protect against respiratory tract infections, support the immune system and is important in musculoskeletal health. 

From March to September it is possible to get vitamin D from outdoor sunlight on skin as food sources can vary. A combination of lockdown, low vitamin D levels in the UK and approaching winter means that people may be vulnerable to COVID-19 this winter. 

Currently there is no evidence to show that Vitamin D can prevent COVID-19. However, Vitamin D’s protective effects from supplementation may help those who are in vulnerable groups and will help protect the population’s musculoskeletal health.  

Provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider

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