Help pregnant choose the right prenatal vitamin
Overview
The plethora of prenatal vitamins can lead to confusion. There are specific recommendations for certain ingredients in prenatal vitamins (e.g., calcium, folic acid, iron, and iodine). Calcium helps with healthy bones, folic acid with brain and spinal cord development, and iron prevents anemia.
- The recommended daily allowances (RDAs) for pregnant women are...
- Calcium 1,300 mg/day (ages 14 to 18 years) and 1,000 mg/day (ages 19 to 50 years),
- Folic acid 600 mcg/day.
- Iron 27 mg/day.
Approach
Key nutrients
Focus on key nutrients. Choose a prenatal with at least 400 to 800 mcg of folic acid, 27 mg of elemental iron, and 150 mcg of iodine per day for most women who are pregnant or planning pregnancy. Give 4 mg per day of folic acid through the first trimester for women at high risk of having a baby with neural tube defects, including those using certain anticonvulsants (carbamazepine, etc).
Folic acid supplementation
- Folic acid supplementation recommendations vary (400 mcg to 4 mg) among organizations and are based on risk of neural tube defects.
- Most women are considered low-risk and should get at least 400 mcg/day (up to 800 mcg/day per some US recommendations).
- In Canada (Canadian guideline), recommend 400 mcg/day (up to 800 mcg/day) for moderate-risk women (e.g., women with diabetes or advanced liver disease, family history of neural tube defects, and those taking certain antiseizure medications like carbamazepine, valproic acid), but increases to 1 mg/day through the first 12 weeks of pregnancy, and then resume at least 400 mcg/day.
- In the US (American guideline), taking certain antiseizure medications places women in the high-risk category. Women at high-risk (e.g., previous delivery of baby with a neural tube defect, and per U.S. recommendations those taking certain antiseizure medications such as carbamazepine, valproic acid) should receive 4 mg/day of folic acid through the first 12 weeks of pregnancy, and then resume at least 400 mcg/day.
- Folic acid supplementation should begin a few months before pregnancy and continued until a few weeks after delivery or throughout breastfeeding.
Omega-3 fatty acids, Calcium & iron supplementation
Feel comfortable suggesting an OTC prenatal (Centrum Specialist Prenatal, Pregnacare Original, Elevit Pronatal, etc). But advise checking labels. Not all prenatals contain iodine and most gummy prenatals don't contain iron. Some prenatal supplements contain omega-3 fatty acids (DHA and/or EPA) and some patients may request a product with omega-3 fatty acids (which includes DHA and EPA) because DHA may theoretically reduce the risk of preterm labor and/or have cognitive benefits for the baby. Don't push prenatals with DHA (docosahexaenoic acid). There's no proof they'll significantly improve cognitive function in kids. Most prenatals don't contain enough calcium to reach the 1000 to 1300 mg/day dose for most pregnant women. Advise making up the difference through diet or an additional calcium supplement.
| Table (1). Dietary Reference Intakes (DRIs) for Vitamins and Minerals for Pregnancy | ||
|---|---|---|
| Vitamin or Mineral | Recommended Daily Allowances (RDA) | Adequate Intake (AI) |
| Vitamin A | 750-770 mcg | ـــــــ |
| Vitamin D | 15 mcg (600 IU) | ـــــــ |
| Vitamin E (alpha-tocopherol) |
15 mg (22.4 IU) | ـــــــ |
| Vitamin K | ـــــــ | 75-90 mcg |
| Folate | 600 mcg | ـــــــ |
| Niacin | 18 mg | ـــــــ |
| Riboflavin | 1.4 mg | ـــــــ |
| Thiamine | 1.4 mg | ـــــــ |
| Vitamin B6 | 1.9 mg | ـــــــ |
| Vitamin B12 | 2.6 mcg | ـــــــ |
| Choline | ـــــــ | 450 mg |
| Biotin | ـــــــ | 30 mcg |
| Vitamin C | 80-85 mg | ـــــــ |
| Calcium | 1000-1300 mg | ـــــــ |
| Iodine | 220 mcg | ـــــــ |
| Iron | 27 mg | ـــــــ |
| Phosphorus | 700-1250 mg | ـــــــ |
| Selenium | 60 mcg | ـــــــ |
| Zinc | 11-12 mg | ـــــــ |
References
- Saldanha LG, Dwyer JT,et al. Is Nutrient Content and Other Label Information for Prescription Prenatal Supplements Different from Nonprescription Products? J Acad Nutr Diet. 2017 Sep;117(9):1429-1436.
- National Institutes of Health. (2020, March 26). Office of Dietary Supplements - Calcium. Nih.gov. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional.
- US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC, Curry SJ, Davidson KW, Epling JW Jr, GarcÃa FA, Kemper AR, Krist AH, Kurth AE, Landefeld CS, Mangione CM, Phillips WR, Phipps MG, Pignone MP, Silverstein M, Tseng CW. Folic Acid Supplementation for the Prevention of Neural Tube Defects: US Preventive Services Task Force Recommendation Statement. JAMA. 2017 Jan 10;317(2):183-189.
- National Institutes of Health. (2017). Office of Dietary Supplements - Iodine. Nih.gov. https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional.
- National Institutes of Health. (2016). Office of Dietary Supplements - Iron. Nih.gov. https://ods.od.nih.gov/factsheets/Iron-HealthProfessional.