Vitamin D in pregnancy

Your baby’s bones grow and form at a rapid rate throughout pregnancy. Vitamin D is a key part of this fascinating and complex process, due to its role in regulating the amount of calcium and phosphate in the body. These nutrients are vital for your baby’s developing bones and help to build strong, healthy teeth.

Your baby’s vitamin D levels at birth depend on your own intake throughout pregnancy. So, as a mum-to-be, you can support your baby’s bones and future health by ensuring you get your recommended daily amount.

The most effective source of vitamin D is sunlight: the body produces it in response to UVB rays on the skin.

However, the latitude of Ireland means the rays are only strong enough during the summer months. Even then, your exposure is likely to be patchy, with various factors at play, including cloud cover, the use of sunscreen, the time of day you go outside, the natural pigmentation of your skin and the coverage you get from your clothes. From October until April, the body relies on any reserves left over from the summer and once these have been used up, other sources are required to maintain an adequate supply.

A few foods provide vitamin D, but these are limited. Oily fish, egg yolks and fortified foods are among the few dietary sources. In Ireland many people find it difficult to get significant amounts from food alone.

Because of this, it’s recommended that all pregnant and breastfeeding women take a vitamin D supplement of 5 micrograms per day. This amount will provide enough for your own needs and help to build the stores your baby needs for the first 6 months of life.

A lack of vitamin D, known as vitamin D deficiency, can result in tiredness and aches and pains. In babies and children, extreme vitamin D deficiency can lead to rickets, a condition characterised by soft bones that don’t develop as they should. A lack of vitamin D has also been linked to long-term conditions such as osteoporosis and diabetes, and other serious diseases.

All women who are pregnant or breastfeeding have an increased risk of vitamin D deficiency and need to pay special attention to getting adequate levels. Taking a daily supplement protects your own health, as well as your baby’s.

If you have dark skin, your increased pigment affects your skin’s ability to generate vitamin D, making a daily supplement even more important. Women of South Asian, African, Caribbean and Middle Eastern descent who live in Ireland are particularly at risk.

IU is a measurement of sun exposure. The table below allows you to compare the vitamin D found in food to sun exposure. 5-10 minutes in the sun is equal to 3000IU, this would be the equivalent of eating three portions of fresh salmon.

Are you are taking a prenatal multivitamin? If so, check that it contains 5 micrograms of vitamin D. If not, talk to your midwife about taking a separate supplement.