What does vitamin D do?

Vitamin D helps control the amount of calcium and phosphate in your body, which are needed to keep your bones, teeth and muscles healthy.

Having too little vitamin D (a deficiency) can affect the way your body absorbs calcium and phosphorus. In children, this can lead to rickets – a condition that can cause bone deformities, such as bowed legs. In adults, vitamin D deficiency can also cause osteomalacia, which can make bones painful and tender.

Where do I get vitamin D?

From late March/April to the end of September, you should be able to get most of your vitamin D from sunlight on your skin. This is because the vitamin forms under your skin in reaction to sunlight. Between October and early March we don't get any vitamin D from sunlight.

Vitamin D is also found in a small number of foods, including:

  • oily fish – such as salmon, sardines, herring and mackerel
  • egg yolks
  • red meat
  • liver 
  • fortified foods with added vitamin D – such as most fat spreads and some breakfast cereals

Another source of vitamin D is dietary supplements. 

Who should take vitamin D supplements?

Some groups of the population are at greater risk of not getting enough vitamin D than others, and the Department of Health recommends that these people should take daily vitamin D supplements.

These groups are:

  • babies from birth to one year of age, who are being breastfed should be given a daily supplement containing 8.5 to 10mcg of vitamin D, to make sure they get enough
  • babies fed infant formula should not be given a vitamin D supplement until they are receiving less than 500mls (about a pint) of infant formula a day, because infant formula is fortified with vitamin D
  • children aged 1-4 years old should be given a daily supplement containing 10mcg of vitamin D 
  • people who are not often outdoors – for example, those who are frail or housebound, or are in an institution such as a care home, or if they usually wear clothes that cover up most of their skin when outdoors should take a daily supplement containing 10mcg of vitamin D

People from minority ethnic groups with dark skin, such as those of African, African-Caribbean or South Asian origin, might not get enough vitamin D from sunlight – so they should consider taking a daily supplement containing 10mcg of vitamin D throughout the year.

Rest of the population

Because vitamin D is found only in a small number of foods, it might be difficult to get enough from foods that naturally contain vitamin D and/or fortified foods alone. So, everyone aged five years and above (including pregnant and breastfeeding women) should consider taking a daily supplement containing 10 micrograms of vitamin D. 

The majority of people aged five years and above will get enough vitamin D from sunlight in the summer (late March/April to the end of September), so you might choose not to take a vitamin D supplement during these months. Find out more about who should take vitamin D supplements and how to take them.

You should continue to give your child a vitamin D supplement until they are five years old. For more information about vitamin D supplements for children, read our page on vitamins for children. If you qualify, you can get free vitamin drops containing vitamin D from Healthy Start vitamins.

Getting advice

Talk to your GP if you're concerned about the level of vitamin D you get from sunlight and your diet. They can advise on whether you need a vitamin D supplement. 

Read the answers to more questions about healthy eating.

Further information:

Page last reviewed: 16/10/2014

Next review due: 15/10/2016