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?
From about late March/early April to the end of September, the majority of people should be able to make all the vitamin D they need from sunlight on their skin.
Children from the age of 1 year and adults need 10 micrograms of vitamin D a day. This includes pregnant and breastfeeding women, and people at risk of vitamin D deficiency.
Babies up to the age of 1 year need 8.5 to 10 micrograms of vitamin D a day.
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 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 10 micrograms of vitamin D during the autumn and winter.
Between late March/early April to the end of September, most people can make all the vitamin D they need through sunlight on their skin and from a balanced diet.
You may choose not to take a vitamin D supplement during these months.
People at risk of vitamin D deficiency
Some people will not make 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 – you may also not make enough vitamin D from sunlight.
You should consider taking a daily supplement containing 10 micrograms of vitamin D throughout the year.
Advice for infants and young children
The Department of Health and Social Care recommends that babies from birth to 1 year of age should have a daily supplement containing 8.5 to 10 micrograms of vitamin D throughout the year if they are:
formula-fed and are having less than 500ml (about a pint) of infant formula a day, as infant formula is already fortified with vitamin D
Children aged 1 to 4 years old should be given a daily supplement containing 10 micrograms of vitamin D.
You can buy vitamin D supplements or vitamin drops containing vitamin D (for under 5s) at most pharmacies and supermarkets.
Women and children who qualify for the Healthy Start scheme can get free supplements containing vitamin D.
See the Healthy Start website for more information.