Function

Vitamin D helps to regulate the amount of calcium and phosphate in the body by adjusting the amounts that are absorbed from the gut and excreted when you go to the toilet. Calcium and phosphate at the right levels are needed to help keep bones and teeth healthy. In addition to this, vitamin D has been linked to a reduced risk of cancer, diabetes and multiple sclerosis. There is also weak evidence of a reduced risk of heart disease. Vitamin D has also been linked to improvements in how the immune system works.

Requirements

• There is no requirement set for adults in the UK
• Pregnant and lactating women are recommended to have 10(µg) micrograms per day

Sources

Vitamin D is unusual in that it can be found in food, like all vitamins, and the body can make it from sunlight. There is no requirement for adults in the UK as it is thought that we can get all we need from sunlight in the summer and store it in our bodies for the winter.

While this may be the case for some of the population, some members of the population are more at risk of not getting enough vitamin D. People with darker skin make less vitamin D than those with paler skin and people who cover their skin all year round for cultural or religious reasons may not get enough exposure to make adequate amounts. It is particularly important to take a supplement if you fall into one of these groups.

Examples of food sources

• Oily fish
• Eggs
• Fortified margarine (check the packet)

Pregnancy Functions and Requirements

Vitamin D helps the body to absorb plenty of Calcium which is important for the baby's bones, especially towards the end of pregnancy when the baby's bones are hardening.

It is important to get enough vitamin D during pregnancy to ensure that your breast milk is rich enough to supply all the baby's needs once they are born.

Infant formula is supplemented with vitamin D by law.

Prolonged deficiency of vitamin D through pregnancy and childhood is associated with an increased risk of rickets: a disease where the bones become soft and deformed. Infants born to women with darker skin or those who cover their skin all year are at grater risk.

Should I be taking a Vitamin D supplement?

Yes- the current advice is that all pregnant and lactating women should take a 10µg supplement. Discuss this with your GP or pharmacist to make sure you are taking one that is appropriate for pregnancy.