What is Vitamin D?
Vitamin D helps regulate the amount of calcium and phosphate in the body.
These nutrients are needed to keep immune system, bones, teeth and muscles healthy.
A lack of Vitamin D can lead to bone deformities such as rickets in children, and bone pain
caused by a condition called osteomalacia in adults.
It's important to take Vitamin D as you may have been indoors more than usual this year.
You should take at least 10 micrograms (400 IU) of Vitamin D a day between October and early March to keep your bones and muscles healthy.
Good sources of Vitamin D
From about late March/early April to the end of September, most people should be able to get all the Vitamin D they need from sunlight.
The body creates Vitamin D from direct sunlight on the skin when outdoors.
But between October and early March we do not get enough Vitamin D from sunlight.
Vitamin D is also found in a small number of foods.
oily fish – such as salmon, sardines, herring and mackerel
fortified foods – such as some fat spreads and breakfast cereals
Another source of Vitamin D is dietary supplements.
In the UK, cows' milk is generally not a good source of Vitamin D because it is not fortified, as it is in some other countries.
How much Vitamin D do I need?
Babies up to the age of 1 year need 8.5 to 10 micrograms of Vitamin D a day.
Children from the age of 1 year need 10 micrograms of Vitamin D a day.
Adults need 10 micrograms of Vitamin D a day. This includes pregnant and breastfeeding women, and people at risk of Vitamin D deficiency.
A microgram is 1,000 times smaller than a milligram (mg).
The word microgram is sometimes written with the Greek symbol μ followed by the letter g (μg).
Sometimes the amount of Vitamin D is expressed as International Units (IU).
1 microgram of Vitamin D is equal to 40 IU. So 10 micrograms of Vitamin D is equal to 400 IU.
Should I take a Vitamin D supplement?
Advice for infants and young children
The Department of Health and Social Care recommends that:
Breastfed babies from birth to 1 year of age should be given a daily supplement containing 8.5 to 10 micrograms of Vitamin D to make sure they get enough
Formula-fed babies should not be given a Vitamin D supplement until they're having less than 500ml (about a pint) of infant formula a day, as infant formula is fortified with Vitamin D
Children aged 1 to 4 years old should be given a daily supplement containing 10 micrograms of Vitamin D
Advice for adults and children over 4 years old
During the autumn and winter, you need to get Vitamin D from your diet because the sun is not strong enough for the body to make Vitamin D. But since it's difficult for people to get enough Vitamin D from food alone, everyone (including pregnant and breastfeeding women) should consider taking a daily supplement containing at least 10 micrograms of Vitamin D during the autumn and winter.
People at risk of Vitamin D deficiency
Some people will not get enough Vitamin D from sunlight because they have very little or no sunshine exposure.
The Department of Health and Social Care recommends that you take a daily supplement containing 10 micrograms of Vitamin D throughout the year if you:
are not often outdoors – for example, if you're frail or housebound
are in an institution like a care home
usually wear clothes that cover up most of your skin when outdoors
If you have dark skin – for example you have an African, African-Caribbean or south Asian background
What happens if I take too much Vitamin D?
Taking too many Vitamin D supplements over a long period of time can cause too much calcium to build up in the body (hypercalcaemia). This can weaken the bones and damage the kidneys and the heart.
If you choose to take Vitamin D supplements, 10 micrograms a day will be enough for most people - unless you have been told you are severely deficient from Vitamin D in your blood.
Do not take more than a daily average of 100 micrograms (4,000 IU) of Vitamin D a day as it could be harmful.
This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17 years.
Children aged 1 to 10 years should not have more than 50 micrograms (2,000 IU) a day.
Infants under 12 months should not have more than 25 micrograms (1,000 IU) a day.
Some people have medical conditions that mean they may not be able to safely take as much. If in doubt, you should consult your doctor.
If your doctor has recommended you take a different amount of Vitamin D, you should follow their advice.
Always remember to cover up or protect your skin if you're out in the sun for long periods to reduce the risk of skin damage and skin cancer.
Vitamin D deficiency cycle
Regular supplementation with Vitamin D is important to prevent recurrent deficiency.