Vitamin D is known as the sunshine vitamin because it’s produced by the action of the sun’s rays on our skin. But long winters and poor British summers mean many of us may be deficient.
What is vitamin D?
Vitamin D is actually a hormone produced by the body. It was named by mistake after it was noticed that rickets could be treated with cod liver oil, which is rich in the vitamin.
While vitamin D is found in certain foods, such as oily fish, milk and eggs, around 90 per cent of our supply comes from the sun – our skin makes vitamin D when it is exposed to ultraviolet B (UVB) rays.
What are the benefits of vitamin D?
Vitamin D is essential for good bone and muscle health, but an increasing amount of evidence has found it may also reduce your risk of osteoporosis, boost your immunity and ward off allergies.
Why aren’t we getting enough vitamin D?
Around 50 to 60 per cent of the British population is deficient in vitamin D. Increasing sun safety awareness – more of us are using sun block – long winters and poor summer sunshine all mean we’re not producing enough of the vital vitamin.
From October to March in the UK, sunlight doesn’t reach the earth at the correct angle, so, in turn, not enough UVB rays reach us in order to produce vitamin D.
Some groups are also more vulnerable. The elderly or housebound, dark skinned, pregnant or breast-feeding women, those who cover their skin and those with a poor diet could be dangerously deficient in vitamin D.
How much vitamin D should I take?
There is no set amount of vitamin D we need every day, mainly because a balanced diet and getting plenty of sunshine during the summer means we should be able to store enough in our body over the winter. However, government advisors – the Scientific Advisory Committee on Nutrition – are currently reviewing the growing data on vitamin D to decide whether we need to increase how much we take.
The committee is considering American research that found those up to the age of 70 may need 600 international units (IU) a day to maintain good health. Research published in the European Journal of Clinical Nutrition also found doubling blood levels of vitamin D could increase average lifespan in the world by two years.
For those at risk of vitamin D deficiency, experts currently advise taking 10 micrograms (400 IU) a day (for children, it’s seven micrograms or 280 IU).
How to get more vitamin D
Getting some summer sunshine is the best way to boost your vitamin D, but there’s no need to sunbathe. Spending around 15 minutes outside without wearing sunscreen (or before you know your skin starts to burn) every day should be sufficient.
You can also add vitamin D-rich foods to your diet:
- oily fish like salmon or mackerel
- eggs and milk
- fortified foods such as spreads, yoghurts and cereals
- tofu and wholegrain cereal are also good choices
- baby formula is fortified with vitamin D by law
You can try taking a vitamin D supplement too, either as a tablet or spray, which delivers the vital vitamin under your tongue and straight into the blood stream. Go for vitamin D3 supplements – the same form produced by the body – rather than D2. Pregnant and breastfeeding women can get vitamin D supplements from their GP.
This article has been adapted from longer features appearing in Healthy, the Holland & Barrett magazine. Advice is for information only and should not replace medical care. Please check with your GP before trying any remedies.