What happens if you don’t take prenatal vitamins while pregnant?

Studies have shown that most women do not get the essential nutrients and vitamins they need through diet alone while pregnant. Prenatal vitamins are meticulously formulated to cater to the heightened nutritional requirements during pregnancy. Their absence can potentially lead to nutrient deficiencies that may affect the health of both the mother and the fetus.

Here are key considerations regarding specific nutrients that support a healthy pregnancy.

What nutrient needs change during pregnancy?


Folic Acid Deficiency: 

  • Effect: Insufficient folic acid in early pregnancy heightens the risk of neural tube defects in the baby, such as spina bifida.
  • Response: Ensuring an adequate folate intake from dark green leafy vegetables, beans, peanuts, whole grains, and salmon is a great start. As prenatal dietitians, we recommend all women take a folic acid supplement, even before getting pregnant. This can reduce the risk of birth defects. 


Calcium Requirements:

  • Effect: Your developing baby needs calcium for bone and teeth formation. And if a baby isn’t getting enough calcium from the mother’s diet, they will get it from Mom’s bones. Calcium deficiency can also increase the mother’s risk of developing high blood pressure or preeclampsia. 
  • Response: The good news is a woman’s body, during pregnancy, absorbs twice the amount of calcium as in normal life. Incorporating dairy products, fortified plant-based milk, leafy greens, and calcium supplements (when advised) can ensure sufficient calcium intake.


Vitamin D:

  • Effect: Vitamin D is vital for calcium absorption and bone health. Inadequate vitamin D can impact both maternal and fetal bone health.
  • Response: Few foods naturally contain Vitamin D. Safe sun exposure, vitamin D-rich foods like fatty fish, liver, vitamin-D enriched dairy products and orange juice, and supplements can maintain adequate vitamin D levels.


Iron and Fatigue:

  •  Effect: Iron deficiency can cause fatigue and reduced energy levels. Severe iron deficiency anemia can increase a woman’s risk of a pre-term birth. It’s also associated with low birth weight and postpartum depression. Women have an increased risk if they have two closely spaced pregnancies, are carrying more than one baby, and are experiencing extreme morning sickness, among other factors.
  •  Response: An iron-rich diet with foods like nuts and seeds, whole grains, legumes, and dark leafy green vegetables with prescribed iron supplements can alleviate these effects.


Omega-3 Fatty Acids:

  • Effect: Omega-3 fatty acids are crucial for the baby’s brain and eye development. Inadequate intake may affect these processes.
  • Response: Consumption of low-mercury fatty fish, flaxseeds, chia seeds, and supplements (if advised) can meet omega-3 requirements.


Overall Nutrient Balance:

In conjunction with a balanced diet, prenatal vitamins ensure a balanced intake of essential nutrients, including vitamins and minerals like vitamin B12, iodine, and zinc. Nutritional inadequacies can contribute to birth defects, preterm birth, low birth weight, and complications. Regular prenatal care, including proper nutrition and supplements when indicated, can mitigate these risks.

Forgoing prenatal care and professional guidance can result in missed opportunities to address nutritional deficiencies and health concerns. Routine prenatal check-ups and discussions with a healthcare provider ensure proper monitoring and intervention as needed.

Where can you get prenatal vitamins?

Some women don’t know they are pregnant for many weeks. Additionally, prenatal vitamins can be costly. No matter what stage of your pregnancy, it’s not too late to begin a supplement program. Here are some foundations that help provide access to prenatal vitamins. If you or someone you know is struggling to purchase prenatal vitamins, don’t hesitate to reach out and ask for help.



Not taking prenatal vitamins during pregnancy can lead to various nutritional deficiencies and health risks for both the mother and the developing baby. Prioritize a balanced diet rich in essential nutrients and consult a healthcare provider for personalized guidance and, if necessary, supplements. Prenatal vitamins are a valuable tool to meet the increased nutritional demands during pregnancy, supporting the health and well-being of both mother and child.