Summer’s here at last, which is great news for all the sun-seekers out there! Being out in the sun is not only a rare treat, but can also be good for you, as it makes your body produce vitamin D. However, this benefit needs to be weighed up carefully against the risks of being in direct sunlight. In this blog I’ll explain how you can get the balance just right.
What is vitamin D?
Vitamin D is a substance that your body turns into hormones, leading to a range of health benefits. Its main actions are to help build strong and healthy bones and to make sure your intestine absorbs important nutrients.
You get vitamin D naturally in two ways. In your diet, oily fish like salmon, sardines and mackerel are the best sources. Fortified cereals and margarines also contain vitamin D and small amounts are found in fish liver oils, shiitake mushrooms and egg yolk. However, your diet can’t provide all the vitamin D you need... which is where the sun comes in!
Sunlight and vitamin D
The sun gives out ultraviolet (UV) radiation, which is made up of UVA, UVB and UVC rays. These vary in strength, and it’s the UVB rays that your body is able to convert into vitamin D. These rays are not around from mid-October to the beginning of April, so the summer is your best opportunity to boost your natural vitamin D.
Sunlight and health risks
As you probably know, the sun also brings with it serious health risks, particularly during the summer months. In some cases it may lead to heat exhaustion or heatstroke, especially if you’re not used to hot weather. It can also cause problems with your eyes.
The most serious harm the sun can cause is to increase your risk of getting skin cancer. UVB rays (the same ones that help you to generate vitamin D) can also damage the DNA in your skin cells. If this DNA damage builds up over time, cells can start growing out of control, which can lead to skin cancer. More than eight out of 10 cases of melanoma (the most serious type of skin cancer) are linked to overexposure to UV rays.
Getting the balance right
So how can you ensure that you get enough sunlight to maintain healthy levels of vitamin D, but not put yourself at risk of health problems?
Current national guidance says that between March and October you can make enough vitamin D by going out in the sun:
- for a short period every day (about 10–15 minutes if you have light skin; a little longer if you have dark skin)
- between 11am and 3pm
- with your forearms, hands and lower legs exposed
- with no sunscreen on
It’s very important not to exceed this recommended amount of time. After any longer, you probably won’t get any extra vitamin D, and will put yourself at risk of burning and causing long-term damage.
Outside of this short period of time, ensure your skin is well protected from UV rays, by following these tips.
- Cover up. Wear loose clothes that cover your skin, and a wide-brimmed hat. Holding clothes up to the light will show you how much sunlight gets through.
- Wear good sunglasses. Choose sunglasses that fit well and have a CE mark confirming that they offer 100% UV protection.
- Use sunscreen. Buy a product that has the letters ‘UVA’ in a circle, is rated at least four stars for protection, and is at least factor 30. Make sure you get good coverage on your skin, and reapply frequently, especially if you’ve been in water.
- Check the UV index. This tells you how strong the UV rays are in your area; you can find it on the Met Office website. If the UV index is above three, you’ll need to take steps to protect your skin.
Getting more vitamin D
Some people, even during the summer, don’t spend long enough outside to maintain healthy levels of vitamin D. In fact, vitamin D deficiency is the most common nutritional deficiency worldwide. It can lead to a lack of bone density, which in serious cases can cause conditions like osteoporosis. It can also increase the risk of cancer, diabetes and heart disease.
If you’re stuck indoors for long periods, for example you’re housebound or have a desk job with long hours or cover your skin for cultural reasons, you may be at risk of vitamin D deficiency. In this case, you will probably benefit from taking vitamin D supplements. If you think you may be at risk, speak to your GP. They will ask you more about your habits and find out if you have any symptoms of deficiency, then decide whether to test your vitamin D levels. You can then buy vitamin D supplements over the counter if your GP decides this is necessary.