Dietary Supplements During Pregnancy: An Informational Overview

Why Nutrition and Supplements Matter During Pregnancy

A balanced diet is the best foundation for a healthy pregnancy. Even with a good diet, however, some nutrients are harder to get in sufficient amounts from food alone. For this reason, health authorities in many countries recommend that pregnant women take certain supplements—most notably folic acid (or folate)—before and during early pregnancy to support the baby’s neural tube development. Other nutrients, such as vitamin D and iron, are often recommended later in pregnancy or throughout, depending on the woman’s status and local guidelines.

It is important to avoid both deficiency and excess. Taking high doses of some vitamins or minerals without medical guidance can be harmful. That is why choosing and dosing supplements should always be done with your healthcare team, who can consider your diet, blood results, and any other health conditions.

Commonly Recommended Supplements in Pregnancy

Folic acid (folate): Folic acid is widely recommended before conception and in the first weeks of pregnancy to reduce the risk of neural tube defects. Many women take a prenatal multivitamin that contains folic acid, or a separate folic acid supplement. The recommended amount varies by country; your doctor will advise the right dose and form (e.g. folic acid vs. methylfolate) for you.

Vitamin D: Vitamin D supports bone health and immune function. Pregnant women who have limited sun exposure or low dietary intake may have low vitamin D levels. Blood testing can help determine if supplementation is needed and at what dose. Do not take high doses without a healthcare provider’s recommendation.

Iron: Iron needs increase during pregnancy. Some women develop iron deficiency and may benefit from an iron supplement prescribed by their doctor. Self-supplementing with iron can be risky because excess iron is not safe; dosage and form should be guided by your obstetrician or midwife based on your blood results.

Omega-3 (DHA/EPA): Omega-3 fatty acids, especially DHA, are often discussed for fetal brain and eye development. Some prenatal supplements include DHA; others take it separately. If you eat little or no fish, your provider may suggest an algal or fish oil supplement. Again, the dose and product should be chosen with professional guidance.

What to Avoid and How to Choose Safe Products

Some supplements and herbs are not considered safe during pregnancy. High-dose vitamin A (retinol) can be harmful to the fetus. Certain herbal products have not been well studied in pregnancy and may pose risks. Always tell your doctor or midwife about every supplement and over-the-counter product you use so they can check for safety and interactions.

When choosing a prenatal or other supplement, look for products that state clear amounts per serving and that have been tested for quality (e.g. third-party certified). Avoid megadoses or combination products with many ingredients unless specifically recommended by your healthcare provider. A simple prenatal that meets local recommendations is often the best starting point, with additional nutrients added only if your provider advises.

Working With Your Healthcare Provider

Your obstetrician, midwife, or family doctor is the best source of advice for your situation. They can order blood tests to check vitamin D, iron, and other nutrient levels, and recommend specific supplements and doses. If you are planning a pregnancy, it is a good idea to discuss nutrition and folic acid before you conceive. During pregnancy, keep a list of all supplements you take and share it at each visit so your care team can ensure everything is safe and appropriate.

This page is intended only to provide general information and does not replace personalised medical or nutritional advice. Always consult a qualified healthcare professional before starting or changing any supplement during pregnancy or when planning to become pregnant.