Iron Supplements During Pregnancy in Canada: What to Know
Short answer: Health Canada advises anyone who could become pregnant, or is pregnant, to take a daily multivitamin with 0.4 mg of folic acid, and in pregnancy that multivitamin should also contain 16 to 20 mg of iron. Your doctor or midwife may check your iron levels during pregnancy and, if they are low, recommend more. Talk to them before adding a separate iron supplement on top of your prenatal vitamin.
Why iron needs are higher in pregnancy
Iron helps to form red blood cells. Health Canada's Dietary Reference Intakes set the Recommended Dietary Allowance (RDA) for iron at 27 mg a day in pregnancy, compared with 18 mg for women aged 19 to 50 who are not pregnant. The 16 to 20 mg in a prenatal multivitamin is meant to be taken on top of the iron you get from food, to help you reach that amount.
| Women 19 and older | RDA for iron (mg a day) | Tolerable upper intake level, UL (mg a day) |
|---|---|---|
| Not pregnant (19 to 50) | 18 | 45 |
| Pregnant | 27 | 45 |
| Breastfeeding | 9 | 45 |
The UL counts iron from food and supplements together. Stomach and bowel upset is the main effect of going above it. A doctor or midwife may prescribe more than the UL to treat iron deficiency; follow their directions.
What Health Canada recommends
- Take a daily multivitamin with 0.4 mg (400 mcg) of folic acid if you could become pregnant or are pregnant.
- In pregnancy, the multivitamin should also contain 16 to 20 mg of iron.
- Ask a health care provider to help you find the multivitamin that is right for you.
- Talk to a health care provider before taking more than 1 mg of folic acid a day. Some people need a higher dose, for example after a pregnancy affected by a neural tube defect.
Testing: when more iron may be needed
A prenatal multivitamin is not a treatment for low iron. A 2021 practice article in the Canadian Medical Association Journal (CMAJ) recommends checking ferritin and hemoglobin at the first prenatal visit and again at about 28 weeks, and describes a ferritin below 30 µg/L as diagnostic of iron deficiency. When iron is low, it lists oral iron as the first-line treatment, with the dose and schedule set by the clinician. If your doctor or midwife recommends an iron supplement, follow their directions and the product label. For how iron testing works, see Iron Deficiency Symptoms: When to Test, Not Guess.
Reading a prenatal label
Find iron in the medicinal ingredients, then multiply the amount per tablet or capsule by the number you take each day. Compare the total with Health Canada's 16 to 20 mg, and ask your doctor or midwife about any difference. Count iron from every other supplement you take as well. Every licensed natural health product sold in Canada shows an NPN on the label; see How to Check an NPN or DIN on Health Canada's Database.
| Prenatal we carry | Label directions | Iron per day at the label dose |
|---|---|---|
| Nestlé Materna Prenatal Multivitamins, 100 Tablets | Women 19 and older: 1 tablet a day with food, before conception, during pregnancy and when breastfeeding | Listed on the box; check it against 16 to 20 mg |
| Materna Prenatal Multivitamin + DHA, 60 Tablets & 60 Softgels | Prenatal tablet plus a separate DHA softgel; follow the package | Listed on the box; check it against 16 to 20 mg |
| NFH Prenatal SAP, 180 Capsules | Adults: 3 capsules a day | 30 mg (10 mg per capsule, from iron glycinate), above the 16 to 20 mg range, so ask your doctor or midwife whether it suits you |
Getting more from the iron you take
- Health Canada advises waiting 1 to 2 hours after a meal before drinking tea or coffee or taking calcium supplements, to improve iron absorption.
- Iron-rich foods include meat, poultry, fish, eggs, beans, peas and lentils, tofu and whole grains. When a meal has no meat, poultry or fish, include a source of vitamin C.
- Iron supplements commonly cause constipation or stomach upset and can darken stools. Tell your doctor or midwife if side effects make it hard to keep taking them; do not simply stop.
If a separate iron supplement is recommended
Our Iron collection lists the forms we carry, for example FeraMAX Pd Therapeutic 150, 100 Capsules (150 mg of elemental iron per capsule) and Wampole Ferrous Fumarate 300 mg, 100 Tablets. Use them in pregnancy only as your doctor or midwife directs. For how the forms differ, read Iron Supplements: Ferrous Fumarate vs Bisglycinate vs Polysaccharide-Iron and Heme Iron vs Non-Heme Iron Supplements: A Canadian Guide. Prenatal multivitamins are in Women's Health & Family Planning and Multivitamins.
Safety
Keep prenatal vitamins and iron supplements out of reach of children. Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6; if a child swallows any, call a doctor or poison control centre right away. Do not take more than one iron-containing product unless your doctor or midwife tells you to.
When to talk to your doctor or midwife
- Before adding any iron supplement to your prenatal multivitamin
- If you think your iron may be low, or you have not had your iron checked
- If side effects make it hard to keep taking iron
- If you have an iron-overload condition, a bowel condition such as ulcerative colitis, or take thyroid medication or antibiotics
- If your prenatal label gives a different amount of iron or folic acid than Health Canada's figures
Sources
- Public Health Agency of Canada. Your Guide to a Healthy Pregnancy.
- Health Canada. Prenatal Nutrition Guidelines for Health Professionals: Iron.
- Health Canada. Dietary Reference Intakes: reference values for elements.
- Health Canada. Iron.
- Malinowski AK, Murji A. Iron deficiency and iron deficiency anemia in pregnancy. CMAJ 2021;193(29):E1137.
- ISMP Canada. Take care with iron supplements.
- Product labels as listed on each product page.
This article is general information, not medical advice. Talk to your doctor, midwife or pharmacist about your own situation.
