Vitamin D is an important nutrient that is needed to keep bones, teeth and muscles healthy. The spread of the coronavirus in the UK and the resultant lockdown has seen vulnerable groups being asked to shield themselves and stay indoors. Are we facing a surge in the numbers of people suffering from vitamin D deficiency?
Vitamin D is often referred to as the ‘sunshine vitamin’. It is mainly synthesised in the skin by the action of sunlight containing UVB radiation. The amount of vitamin D obtained from sunlight exposure is thought to be around 90%. From about late March to the end of September, most people are able to get all the vitamin D they need from sunlight.
Between October and early March people do not get enough vitamin D from sunlight alone. It is found in a small number of foods such as oily fish, red meat, liver, egg yolks and fortified foods, such as most fat spreads and some breakfast cereals. Some individuals are more at risk of vitamin D deficiency and are advised to take a daily supplement of vitamin D throughout the year. This includes babies, young children and pregnant women, and people who:
- Are not often outdoors – for example, frail or housebound
- Are in an institution like a care home
- Usually wear clothes that cover up most of the skin when outdoors
- Have dark skin – for example, an African, African–Caribbean or south Asian background.
Vitamin D supplements are widely available in supermarkets, chemists and health food shops. In the UK, pregnant women, women with a child under 12 months and children aged up to four years who are receiving Healthy Start vouchers are entitled to free vitamins.
A study published in May suggested that vitamin D can support the immune system through a number of immune pathways involved in fighting coronavirus. The authors highlighted that many recent studies have confirmed the pivotal role of vitamin D in viral infections and proposed that optimising vitamin D levels will benefit bone and muscle health, and could help to fight off the virus.
When the UK was formally put into lockdown on 23 March, households were advised by the government to stay at home to protect the NHS and help save as many lives as possible. With families being asked to stay indoors and only being allowed out to exercise once per day, the risk of vitamin D deficiency has been raised as a potential health issue.
We have just come out of the winter months in the UK, and would usually be able to start accumulating our levels of vitamin D outdoors during the summer. Therefore, the UK government health departments have updated their advice on vitamin D supplementation, and it is now recommended that everyone should consider taking 10 mcg of vitamin D a day to keep their bones and muscles healthy throughout the duration of the pandemic. It is especially important that people at risk of deficiency maintain sufficient levels of vitamin D during the lockdown, particularly if they do not have access to a garden or private outdoor space.