How to get vitamin D from sunlight

Vitamin D is essential for healthy bones, and in the UK from around late March/early April to the end of September we get most of our vitamin D from sunlight exposure. Find out how to get enough without risking sun damage.

We need vitamin D to help the body absorb calcium and phosphate from our diet. These minerals are important for healthy bones, teeth and muscles.

A lack of vitamin D – known as vitamin D deficiency – can cause bones to become soft and weak, which can lead to bone deformities. In children, for example, a lack of vitamin D can lead to rickets. In adults, it can lead to osteomalacia, which causes bone pain and tenderness.

How do we get vitamin D?

Our body creates vitamin D from direct sunlight on our skin when we are outdoors. From about late March/early April to the end of September, most of us should be able to get all the vitamin D we need from sunlight.

We also get some vitamin D from a small number of foods, including oily fish such as salmon, mackerel, herring and sardines, as well as red meat and eggs. 

Vitamin D is also added to all infant formula milk, as well as some breakfast cereals, fat spreads and non-dairy milk alternatives. 

The amounts added to these products can vary and may only be added in small amounts. Manufacturers must by law add vitamin D to infant formula milk.

Another source of vitamin D is dietary supplements.

How long should we spend in the sun?

Most people can make enough vitamin D from being out in the sun daily for short periods with their forearms, hands or lower legs uncovered and without sunscreen from late March or early April to the end of September, especially from 11am to 3pm.

It's not known exactly how much time is needed in the sun to make enough vitamin D to meet the body's requirements. This is because there are a number of factors that can affect how vitamin D is made, such as your skin colour or how much skin you have exposed. But you should be careful not to burn in the sun, so take care to cover up, or protect your skin with sunscreen, before your skin starts to turn red or burn.

People with dark skin, such as those of African, African-Caribbean or south Asian origin, will need to spend longer in the sun to produce the same amount of vitamin D as someone with lighter skin.  

How long it takes for your skin to go red or burn varies from person to person. Cancer Research UK has a useful tool where you can find out your skin type, to see when you might be at risk of burning.

Your body can't make vitamin D if you are sitting indoors by a sunny window because ultraviolet B (UVB) rays (the ones your body needs to make vitamin D) can't get through the glass.

The longer you stay in the sun, especially for prolonged periods without sun protection, the greater your risk of skin cancer.

If you plan to be out in the sun for long, cover up with suitable clothing, wrap-around sunglasses, seeking shade and applying at least SPF15 sunscreen.

Winter sunlight

In the UK, sunlight doesn't contain enough UVB radiation in winter (October to early March) for our skin to be able to make vitamin D.

During these months, we rely on getting our vitamin D from food sources (including fortified foods) and supplements.   

Using sunbeds is not a recommended way of making vitamin D.

Babies and children

Children aged under six months should be kept out of direct strong sunlight.

From March to October in the UK, children should:

• cover up with suitable clothing, including wearing a hat and wearing wrap-around sunglasses
• spend time in the shade (particularly from 11am to 3pm)
• wear at least SPF15 sunscreen

Source:.nhs.uk/Livewell/Summerhealth/Pages/vitamin-D-sunlight.aspx