The Real Reason Prenatal Vitamins Can Worsen Morning Sickness

Prenatal vitamins are recommended for pregnant women to supplement key nutrients necessary for growing a baby, as explained by the Mayo Clinic. It is even encouraged to start taking these essential pills three months before getting pregnant, if possible, to ensure the body has high enough levels of two nutrients in particular, folic acid and iron. The former is heavily involved in the early formation of the brain and spinal cord while the latter supports blood-cell formation, allowing oxygen to make its way to the fetus. Folic acid is so imporant, in fact, that this 2011 review of scientific studies states that the nutrient can also protect against preterm birth and congenital heart defects. Your prenatal vitamin should have at least 400 micrograms of folic acid and 27 milligrams of iron, states Penn Medicine Lancaster General Health.

Folic acid and iron aren't the only vitamins and minerals found in prenatal vitamins — the Mayo Clinic outlines several others that you should look for in a good vitamin, including vitamin D, vitamin C, vitamin A, vitamin E, zinc, iodine, and the family of B vitamins. If a prenatal vitamin doesn't contain omega-3 fatty acids and your diet lacks them, you should also look for a separate supplement to ensure your baby gets enough of this nutrient, essential for proper brain function.

Unfortunately, taking prenatal vitamins can have some side effects, including headaches, digestive discomfort, and joint pain, as per Healthline. They can also worsen morning sickness.

Verywell Family spoke to assistant professor of obstetrics and gynecology Amy M. Valent about the side effects of taking prenatal vitamins. Valent explained why some pregnant women may experience worsened morning sickness after popping their daily dose. She says that the size of the pill as well as its scent are common triggers for nausea. While swallowing, the pill may act upon the body's gag reflex. If swallowed, the lingering taste may also lead to nausea due to the preservatives found in the supplement.

While Valent pointed out to Verywell Family that it is rare that the micronutrients found in the pill are the culprit of worsened morning sickness, Kin Fertility explains that one of these micronutrients — iron — can, in fact, have this effect. In larger doses, iron can lead to stomach distress and a general feeling of being unwell. The outlet also outlines certain underlying conditions as reasons why morning sickness might be triggered upon swallowing a prenatal vitamin. These include acid reflux and thyroid disorders.

If you notice yourself feeling sick after taking your prenatal vitamin, there are ways you can minimize this effect. Verywell Family recommends switching manufacturers until you find a vitamin with minimal side effects in addition to experimenting with the time of day that you take it. You can also try splitting the dose to take at different points of the day as well as taking the pill with a meal.