What does vitamin D do?

Vitamin D has several important roles – for example, it helps control the amount of calcium and phosphate in your body, which are needed to keep your bones and teeth healthy.

Having too little vitamin D (a deficiency) can damage 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 cause rickets (otherwise known as osteomalacia or weak bones), which can make bones painful and tender.

Where do I get vitamin D?

You get most of your vitamin D from sunlight on your skin. This is because the vitamin forms under your skin in reaction to sunlight. Vitamin D is also found in a small number of foods, including:

  • oily fish
  • eggs
  • fortified foods that have had vitamin D added to them – such as breakfast cereals and powdered milk

Who is at risk of vitamin D deficiency?

Most people can get all the vitamin D they need by eating a healthy, balanced diet and getting a little sunlight. However, the Department of Health recommends a daily vitamin D supplement for the following people:

  • all children aged six months to four years (see below)
  • all pregnant and breastfeeding women 
  • all people aged 65 and over 
  • people who aren’t exposed to much sun – for example, people who cover up their skin for cultural reasons, or people who are housebound (stay indoors) for long periods of time

Vitamin D for babies and children

The Department of Health and the Chief Medical Officers recommend a dose of 7-8.5 micrograms (approximately 300 units) for all children aged six months to five years.

If you are exclusively breastfeeding your baby, you should give your baby a daily vitamin D supplement from the age of six months.

If your baby is fed with infant formula, you should give them a daily vitamin D supplement if they are drinking less than 500ml (one pint) of formula a day.

If you are breastfeeding your baby and giving them infant formula as well, they will need a daily vitamin D supplement from the age of six months, or if they are drinking less than 500ml (one pint) of formula a day.

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