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Dietary Supplements During Pregnancy

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 Most pregnant women are prescribed a daily vitamin and mineral supplement to meet their extra nutritional needs.  

Talk to your healthcare provider to ensure you get enough of the essentials, including folic acid, Vitamin B12 and iron.

If you can’t afford prenatal supplements, talk to your health care provider or your local public health office. There may be a prenatal program that provides these supplements at no cost.

Tell your health care provider about any herbal supplements or remedies, natural health products or vitamin and mineral supplements you're taking. Some may be harmful to your baby, even if they are natural. Taking too much of any supplement may also be harmful. Be sure to keep all supplements out of the reach of children.

Folic Acid 

  • Health Canada recommends all women of childbearing age take a multi vitamin with 0.4 milligrams (400 micrograms) of folic acid every day.
  • Health Canda also recommends a diet rich in folate - one of the B vitamins found in foods-such as dark green vegetables, beans, lentils, orange juice and some grain products. Folic acid is the form of folate found in vitamin supplements.  
  • Folic acid and folate are important for the healthy growth of an unborn baby's spine, brain and skull, especially during the first four weeks of pregnancy. 
  • Women who take a folic acid supplement and eat a diet rich in folate before becoming pregnant and during the first few weeks of pregnancy have a smaller chance of having a baby born with an Open Neural Tube Defect. 
  • During pregnancy, some women may need more than 0.4 milligrams of folic acid.  Talk to your healthcare provider about your specific needs.
  • Don’t take a multivitamin or folic acid supplement with more than 1000 micrograms or 1 milligram of folic acid unless it's advised by your doctor or midwife.

For more information about folic acid, see the HealthLink BC: Folic Acid Test Overview.


Your supplement should contain 16-20 mg of iron.  Some women may need more. Talk to your healthcare provider to find out how much you need. An iron supplement:

  • Is best absorbed between meals with a light snack high in vitamin C (such as berries, citrus fruits, peppers, broccoli, or tomatoes).
  • Should not be taken with tea or coffee.
  • Should not be taken with foods high in calcium like milk, yogurt or cheese, or with your calcium supplements.
  • May cause nausea if you take it on an empty stomach.
  • May cause constipation. 

Include food sources of iron, like meat, fish and poultry, in your diet every day. Plant-based foods like beans, lentils and dark green leafy vegetables also have iron. Eat these foods with a source of vitamin C, like oranges, kiwis and bell peppers, to better absorb iron. 

Vitamin A

Too much vitamin A can harm your baby. Your prenatal supplement should't have more than 10,000 IU of preformed vitamin A (often listed as acetate, succinate or palmitate). Avoid fish liver oils, such as cod liver oil. They might have too much Vitamin A.

Calcium and Vitamin D

Your healthcare provider may recommend a calcium and vitamin D supplement. This will depend in part on how much calcium and vitamin D you get from food.  For more information, see the HealthLink BC file Food Sources of Calcium and Vitamin D

Essential Fatty Acids (EFA)

EFAs are important during pregnancy and breastfeeding and help your baby’s nervous and visual system development. EFAs can be found in fish, walnuts, soybeans, tofu, ground flax seed and Omega 3 enriched eggs. They can also be found in vegetable oils, such as canola, flaxseed and soybean oils, and in non hydrogenated margarines and salad dressings made from canola or soybean oil.

Fish is an excellent source of EFAs and other nutrients. Canada’s Food Guide recommends that pregnant women continue to eat 150 grams (five ounces) of cooked fish each week. Choose fish that’s low in mercury.

If you don’t eat fish, talk to your healthcare provider to help ensure you get enough EFAs during your pregnancy.

Resources and Links:

HealthLink BC: Iron and Your Health
HealthLink BC: Pregnancy and Nutrition - Folate and Neural Tube Defects
HealthLink BC: Healthy Eating - Choose Fish Low in Mercury 

Last Updated: August 4, 2013