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Why do I need vitamin D in pregnancy?Vitamin D helps to regulate the levels of calcium and phosphate in your body. You need calcium and phosphate to keep your bones and teeth healthy.
Not having enough vitamin D when you are pregnant or breastfeeding may prevent your baby from getting enough calcium and phosphate(SACN 2011). This can cause him to develop weak teeth and bones, and in rare cases, develop rickets (Holick and Chen 2008, RCOG 2009, SACN 2011, Stanner et al 2012).
Vitamin D can help you to fight infections, and may help to prevent diabetes and some cancers (Cannell et al 2006, Heaney 2007, Holick 2004, Holick and Chen 2008. RCOG 2009).
There may be a link between low vitamin D levels during pregnancy and an increased risk of having a baby with a low birth weight (Christensen et al 2012, De-Regil et al 2012).
How do I get vitamin D?You can get vitamin D in two ways.
Your body makes most of its vitamin D through exposure to sunlight in the months between April and October, in the hours between 11am and 3pm, depending on where in the UK you live. The further north you live, the less time the sun is at the correct angle to make vitamin D.
Try to expose at least your face and forearms to sunlight for at least 20 minutes a day, without sunblock, during the summer months. This will build up enough vitamin D stores to last you throughout the winter months.
How long you can stay in the sun without sunscreen depends on a few individual factors, but make sure that you cover up and protect your skin with sunscreen before your skin turns red or burns (NHS Choices 2011).
What you eat and drink(SACN 2007) provides you with some vitamin D. Good sources are oily fish such as salmon, mackerel and sardines (Holick and Chen 2008). You should eat two portions of fish a week, one of which should be oily. Red meat and egg yolks also provide some vitamin D.
Certain varieties of margarines and breakfast cereals are fortified with vitamin D(RCOG 2010), so check the nutritional information on the packet.
During winter, the sun is not at the right angle to produce rays that can stimulate vitamin D production in our skin. So you need to get vitamin D from the food you eat to top up your body's stores (Ruston et al 2004, SACN 2007).
Do I need to take a vitamin D supplement in pregnancy?It's recommended that you take a supplement containing 10 micrograms (mcg) of vitamin D every day during pregnancy and while you're breastfeeding (NCCWCH 2008, SACN 2011).
It's very common for women in the UK to have lower than recommended levels of vitamin D. One in four women between the ages of 19 and 24, and one in six between 25 and 34, have lower than recommended levels of vitamin D in their blood. This means that they are at risk of having a vitamin D deficiency (DH 2011).
You are more likely to have low levels of vitamin D, and be in need of a vitamin D supplement, if you:
- Are of south Asian, African, Caribbean or Middle Eastern descent.
- Don't get much exposure to sunlight, for example if you cover yourself when you are outside, or always wear sunscreen.
- Don’t eat enough vitamin D-rich foods, such as oily fish, eggs, meat, vitamin D-fortified margarine, or breakfast cereals.
- Have a body mass index (BMI) of 30 or above (NCCWCH 2008, CMACE/RCOG 2010, Vimaleswaran et al 2013).
Most pregnancy multivitamins contain vitamin D. Or, if you prefer, you can take a single vitamin D supplement.
Only take a multivitamin that's made specifically for pregnancy, and check the label to see how much vitamin D it contains. Ask your pharmacist, midwife or doctor if you're not sure which one is suitable.
If you don't take a vitamin D supplement in pregnancy, and go on to breastfeed your baby, your baby may not have as much vitamin D as he needs in his first few months of his life. If this is the case, your doctor or midwife may recommend that your baby has a daily dose of vitamin D from when he is a month old (DH 2009, NHS 2011).
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