What's the deal with Vitamin D & COVID-19?

The COVID-19 pandemic has highlighted the need to ensure the population maintains a healthy balanced diet and regular exercise in the fight against the virus. The NHS guidelines report that individuals with a high body mass index (BMI >40kg/m2) are at greater risk of developing poorer COVID-19 outcomes than those with a lower BMI (NHS, 2020).

In addition, the news has previously highlighted a possible link between low Vitamin D status in patients suffering with the most severe COVID-19 symptoms, with recent calls for universal Vitamin D supplementation amongst the general population in a bid to reduce poor COVID-19 outcomes (Guardian, 2021).

In December 2020, NICE, PHE and SACN produced a rapid review to explore the potential positive effects Vitamin D may have in the battle to control COVID-19. The report concluded ‘it was not possible to determine a direct relationship between Vitamin D and COVID-19 based on the available evidence’ (NICE, 2020). However calls from the scientific community have recommended that ‘NICE should continue to monitor new evidence as it is peer-reviewed and published, including results from several clinical trials on Vitamin D and COVID-19 outcomes that are currently underway’ (The Lancet, 2021).

So what do we know about Vitamin D and why is it important for health?

Vitamin D Facts

What is it?

Often referred to as the ‘sunshine’ vitamin, as we absorb the majority of our Vitamin D from sunlight through our skin. Vitamins, whilst they don’t contain any energy, help our body function. Vitamin D works alongside calcium and phosphorus to help develop and maintain healthy bones, muscles and teeth. It also helps protect muscle strength, preventing rickets, osteomalacia and falls (BDA, 2019).

Where can you get Vitamin D?

Foods that contain Vitamin D include:

• Oily fish such as salmon, sardines, pilchards, trout, herring, kippers and eel
• Cod liver oil (but don’t take this if you are pregnant)
• Egg yolk, meat, offal and milk contain small amounts but this varies during the seasons
• Margarine, some breakfast cereals, infant formula milk and some yoghurts have added vitamin D

As Vitamin D sources in foods aren’t great it is recommended that all adults and children (over 1 years) take a daily supplement rather than relying solely on food sources to reach the recommended amount of daily Vitamin D.

How much do you need?

Current recommendations for the general population are 10 micrograms (mcg) per day during the ‘winter months’, which for the UK are classified as October to March.

At risk groups should consider a supplement all year round and babies under 1 should be given a daily supplement unless they are consuming more than 500 mls of formula milk (BDA, 2019)

Is anyone more ‘at-risk’?

Yes, there are groups of the population that are more ‘at-risk’ of low Vitamin D status. These include:

• Babies and young children who spend little time outside
• Older adults and nursing home residents including people over 65 (as their skin isn’t as good at making Vitamin D)
• Black, Asian, and minority ethnic populations
• Anyone who spends little time outside

Vitamin D supplements are available from the government for those individuals who are classified in the ‘clinically extremely vulnerable’ category and supplements are available to buy at supermarkets and pharmacies.

If you are concerned you are not getting enough Vitamin D, speak to your doctor, health visitor, or ask to be seen by a dietitian or registered nutritionist for more detailed advice.

Dr Sarah Hillier, Course Leader, Applied Human Nutrition, Faculty of Sport, Health and Social Sciences.