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How To Pick a Prenatal Vitamin

September 08, 2021

If you’re thinking about having a baby, the best time to start taking prenatal vitamins is before you are pregnant. And while most prenatal vitamins are similar, it’s important to find one that is right for you.

Coupled with a healthy diet, the nutrients contained in prenatal vitamins assist in all aspects of fetal growth, from limbs to the central nervous system to brain function.

Look for These in Your Vitamin

Folic Acid. This supports brain and nervous system development and helps protect against fetal abnormalities such as spina bifida and hydrocephalus. Look for a minimum of 400 micrograms a day.

Calcium. The recommended daily intake of calcium is 1000 milligrams a day for the development of teeth and bones. In addition to your prenatal vitamin, incorporate milk, fortified orange juice and leafy greens into your diet for extra calcium.

Vitamin D. To support fetal teeth and bone growth, you’ll need 600 international units (IU) of vitamin D a day. If you have a vitamin D deficiency, your physician may recommend a supplement containing 1000 to 2000 IU per day.

Vitamin C. While helping support immune function, vitamin C also aids in the healthy development of cartilage, tendons, bones and skin.

Vitamin A. This is the vitamin most responsible for eyesight and overall fetal development.

Iron. While preventing anemia, iron aids in the creation of blood supply that allows for a healthy flow of oxygen to the fetus.

Zinc. Zinc is essential for immune support.

Iodine. Iodine supports maternal thyroid function as well as fetal central nervous system and brain development.

When to Start Taking a Prenatal Vitamin

As most fetal organ growth takes place during the first trimester, the ideal time to begin taking a prenatal vitamin is one to three months before conception. Many women don’t realize they are pregnant until missing their period, about six weeks into pregnancy, so ensuring the right vitamins and minerals are present during those early days is vital. Especially if you are deficient in certain nutrients, such as vitamin D or folic acid, it’s important to supplement the body before the onset of pregnancy to help avoid fetal abnormalities.

Common Side Effects


High progesterone levels during pregnancy slow down everything in your body, including bowel movement. This makes constipation one of the most common complaints. The iron in prenatal vitamins can worsen constipation. Stool softeners can alleviate this issue.

Nausea and Vomiting

Prenatal vitamins can be difficult to digest, which can exacerbate common first trimester symptoms such as nausea and vomiting. 

Pregnant? Avoid These Vitamins and Supplements

A prenatal vitamin is typically the only supplement you need during pregnancy, but it’s important to talk to your OB-GYN to ensure that you aren’t experiencing specific deficiencies. For example, if bloodwork indicates anemia, a supplement may be recommended in addition to your prenatal vitamin depending on the deficiency’s severity.

In contrast, too much of certain vitamins and minerals can be detrimental to the pregnancy and/or fetal health. In some cases, these can lead to congenital abnormalities. For example, too much vitamin A can cause limb defects, too much iodine can affect thyroid development and high levels of vitamin E have been associated with premature rupture of membranes. Be sure to take only the recommended daily dosage.

Additionally, certain natural supplements like black cohosh root and dong quai root that contain high levels of estrogen can also be associated with early contractions. Discuss supplements during pregnancy with your OB-GYN before adding anything to your daily regimen.

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