Boots WebMD Partners in Health
Return To Boots

Vitamins & minerals health centre

Vitamin D deficiency

What is vitamin D deficiency?

Vitamin D is essential for healthy bones. We get some of it from food, but most comes from sunlight. Some people don't have enough vitamin D - called vitamin D deficiency.

Between October and March, the sunlight in Britain is not strong enough to make enough vitamin D, and up to a quarter of the population has low levels of it in their blood.


Symptoms of vitamin D deficiency

Vitamin D deficiency can put people at risk of:

  • Rickets bone problems in children
  • Osteomalacia bone problems in adults

Some research suggests that not getting enough of it may also be linked to:

Vitamin D deficiency at-risk groups

The Chief Medical Officers of the UK say these groups are at particular risk of vitamin D deficiency:

  • Pregnant and breastfeeding women, especially teenagers and young women.
  • Infants and children under 5 years of age.
  • People 65 and over.
  • People who have little or no exposure to the sun. This includes covering-up for cultural reasons, people who are housebound or who stay indoors for long periods of time.
  • People with darker skin, such as African, African-Caribbean and South Asian origin. These groups are not able to make as much vitamin D as those with paler skin.

Blood test for vitamin D deficiency

The most accurate way to measure how much vitamin D is in your body is a blood test to measure 25-hydroxy vitamin D in your bloodstream. This is a form of vitamin D produced in the liver. In the kidney, 25-hydroxy vitamin D is converted into an active form of the vitamin for use by the body to help control calcium and phosphate levels.

Safe sun exposure

Around 10 to 15 minutes a day in the summer sun without sunscreen is enough to top up vitamin D levels for most people. Health officials don't give firm recommendations on the duration because the ideal amount of sun depends on people's skin type and how quickly they get sun burn. People with darker skin need longer in the sun than those with lighter skin.

The best time of day for making vitamin D from sunlight is 11am to 3pm, April to September.

It doesn’t require putting on a bikini or trunks, but the larger the area of the body uncovered, the more of the vitamin the body makes.

Other than a daily vitamin top-up, the usual sun protection measures should be taken, including using sun protection factor of at least SPF 15.

However this will not provide sufficient vitamin D during the winter months.

WebMD Medical Reference

Stay informed

Sign up for BootsWebMD's free newsletters.
Sign Up Now!

Popular slideshows & tools on BootsWebMD

How to help headache pain
rash on skin
Top eczema triggers to avoid
boost your metabolism
Foods to lower LDL (bad) cholesterol
Tips to support digestive health
woman looking at pregnancy test
Is your body ready for pregnancy?
sick child
Dos and don'ts for childhood eczema
Treating your child's cold or fever
bucket with cleaning supplies in it
Cleaning and organising tips
adult man contemplating
When illness makes it hard to eat
woman holding stomach
Understand this common condition
cold sore
What you need to know