Calcium and vitamin D in pregnancy

Calcium and vitamin D are a bit of a double act in pregnancy: calcium builds your baby’s bones and teeth, and vitamin D helps your body absorb and use that calcium. Getting enough of both supports your baby’s development and protects your own bones too — because if you don’t take in enough calcium, your body will draw on your own stores to supply your baby.

Calcium. Your baby’s skeleton is growing rapidly, especially in the third trimester, and calcium is the building block. The good news is that most people can get enough from food, so it’s usually about making sure calcium-rich foods are a regular part of your day:

• Dairy — milk, cheese and yoghurt are the classic sources (hard cheeses and pasteurised dairy are fine in pregnancy).
• Calcium-fortified plant milks and other fortified foods, which are great if you don’t do dairy — just check the label says “added calcium”.
• Tinned fish with soft, edible bones, like salmon and sardines.
• Tofu (calcium-set), leafy green vegetables, almonds, and legumes.

Aim to include a few serves of calcium-rich foods across the day. If you’re vegan, dairy-free or don’t eat much of these, it’s worth checking with your GP, midwife or a dietitian about whether you’re getting enough, and whether a supplement would help.

Vitamin D. Vitamin D is different, because we make most of it from sunlight on our skin rather than from food (there’s a little in oily fish, eggs and fortified foods). That makes deficiency surprisingly common — particularly if you have darker skin, cover up for cultural or sun-safety reasons, spend most of your time indoors, or are pregnant through winter or in southern parts of Australia. Low vitamin D can affect how well you absorb calcium, and is linked with some pregnancy complications.

Because you can’t easily tell if you’re low, vitamin D is often checked with a blood test in pregnancy, especially if you have any of those risk factors — and if your level is low, your GP or midwife will recommend a supplement to top it up. Sensible sun exposure helps too, balanced with sun safety (Australia’s strong sun means you don’t need much, and you should still avoid burning).

Do you need supplements? For calcium, most people don’t if they’re eating enough calcium-rich food — but a supplement can fill the gap if your diet is low. For vitamin D, supplementation is guided by your blood test and risk factors rather than taken by everyone automatically. As with all supplements, it’s best to be guided by your care team rather than self-prescribing, and to remember that food comes first where it can.

Putting it together: enjoy a few serves of calcium-rich foods each day, get a little safe sun for vitamin D, and let your antenatal blood tests flag if your vitamin D needs a boost. If you follow a restricted diet or have risk factors for low vitamin D, raise it with your GP or midwife — a simple test and, if needed, a supplement, keeps both you and your baby’s bones well supplied.