Prenatal vitamins are formulated so that pregnant women can obtain all the micronutrients they require to keep their body growing and support the developing baby (1).
Not to mention, they may help deal with the hormonal changes occurring during pregnancy that can lead to anemia, morning sickness, and other unpleasant side effects (2). Even the federal government recommends prenatal vitamins during pregnancy (3).
The best time to take them is before you conceive. This is because the baby’s brain and spinal cord are developed in the first month – which makes it imperative to have adequate nutrients on board early on. Many pregnant women don’t even know they are pregnant until after this critical time period.
1Folate helps support healthy baby growth. Folate actually comes in several forms. The naturally occurring folate and the synthetic methylfolate (the active form) or standard folic acid. While synthetic, folic acid and methylfolate are more stable than food-based folate and absorbed 1.67 times as well (4).
Folate is essential for cell growth and works with B12 to make red blood cells. Red blood cells that deliver oxygen to you and your baby, making this necessary for both of your lives.
Most notably, a 2013 study published in the Journal of the American Medical Association demonstrated that folate prevents neural tube defects, such as anencephaly and spina bifida, by 50-70% (5).
Another 2011 study also showed that folic acid intake in early pregnancy was associated with a lower risk of language difficulty in 3 year old children (6). More recent studies show a link between folic acid intake and reduction of autism spectrum disorder (7).
2Vitamin B12 can help fetus development. B12 deficiency can lead to anemia – making you feel tired, slow, and lousy. B12 deficiency during pregnancy can result in major complications including low birth weight and preterm birth (8).
Studies also demonstrate that those with B12 deficiency double their risk for developing depression.
Another 1963 study, which still holds true today, shows that B12 is needed for nervous system development and red blood cell formation – making it essential for pregnant women (9).
Without enough iron in your diet, you can become anemic because your body prioritizes your growing baby’s oxygen demands.
Iron is present in both heme and non-heme forms. Heme iron is primarily found in meat and is more easily absorbed. Non-heme iron is present in plants and is absorbed more poorly. Increase non-heme iron absorption by pairing it with vitamin C rich foods like bell peppers, citrus, berries, lemon juice or raw broccoli.
Lastly, supplementing with iron to prevent anemia has been shown to cut the risk of preterm delivery, infant and mother mortality. Iron deficiency has also been shown to irreversible affect cognition in the the developing baby (11).
4Calcium is the key for hormone signaling cascades and a healthy skeleton. A study done in 1996 shows that calcium plays a hand in bone growth, cell signaling, muscle contractions, and even blood clotting- just to name the main functions (12). New research also supports the role of calcium, especially when combined with the right amount of vitamin D, in promoting optimal fetal development (13).
5Prenatal vitamins should include zinc and copper for optimal health if iron is included. A 2008 study showed that as iron supplementation increases (pregnant women need approximately 50% more than non-pregnant women), zinc and copper absorption seems to be negatively affected (14). Newer research has confirmed that iron supplementation can reduce copper stores in breastfeeding women (15). Low levels of iron, zinc, copper and calcium are associated with poor pregnancy outcomes (16).
It becomes extremely important then to increase your intake of copper and zinc when supplementing with iron.
6Prenatal vitamins supplemented with fiber may help prevent excessive pregnancy weight gain and nourish gut bacteria. A study published in the International Journal of Obesity showed that high fiber foods slow down digestion, increase satiety, nourish gut bacteria, and are associated with less weight gain over time, which may help prevent excess pregnancy weight gain (17).
The more time it takes to break down your food, the less of a rise you will have in your blood sugar and the longer you will feel full after eating (18).
7Fiber helps prevent gestational diabetes. A 2015 study involving 249 pregnant women showed that adequate fiber intake in addition to regular intake of fruits, vegetables, and unsaturated fats resulted in a lower risk of gestational diabetes (19).
8 Fiber helps feed your “good” gut bacteria. A 2013 study showed that fiber nourishes your gut’s healthy bacteria. This bacteria can actually break down the fiber you eat and turn it into by-products that improve your weight and help prevent chronic disease (20).
9Pre- and probiotics help supercharge the microbiome. A study published in Nutrients showed the probiotics can provide and increase the absorption of vitamin K, vitamin B12, protein, and nutrients that fight cancer or reduce inflammation (21).
Probiotics have also been shown to assist with constipation and food cravings (22, 23). Research also shows pre- and probiotics can influence the baby’s microbiome and prevent health conditions like colic and food allergy (24).
There are probiotic supplements you can purchase, but by eating more fiber-filled, fermented foods, you’ll naturally feed and grow the bacteria in your gut. Good choices include kimchi, sauerkraut, yogurt, and others. For certain situations, like after taking antibiotics or with a history of dysbiosis (frequent yeast or gastrointestinal infections), it may make sense for you to call in the troops and invest in a concentrated probiotic supplement providing more than 40 billion microorganisms per dose.
10Essential fatty acids help build healthy brains and nervous systems. Essential fatty acids are not produced by the body, meaning it’s essential to eat them in our daily diet (25).
Unfortunately, many prenatal vitamins do not include these essential fatty acids. This is problematic because studies show that the two long-form essential fatty acids, DHA and EPA, are needed to build up your baby’s brains, eyes, and nervous system (26, 27).
A 2005 study showed that consuming fish that have natural levels of these essential fatty acids may increase your consumption of contaminants such as BPA or heavy metals (28). It is therefore best to avoid large-size fish such as tuna
11Ginger can alleviate morning sickness. A 1992 study published in the Journal of Clinical Endocrinology and Metabolism showed that the hormonal changes from estrogen and human chorionic gonadotropic (hCG) hormone during pregnancy stimulates hyperthyroid activity and can lead to severe vomiting and nausea in some women, known as hyperemesis gravidarum (29). Untreated hyperemesis gravid arum may result in weight loss and electrolyte imbalance, with risks to the pregnancy (30).
A 2009 study showed that about 80% of pregnant women experience nausea during the day mostly between the 6th and 12th week of pregnancy (31).
Increasing the amount of ginger you consume, found in some prenatal supplements, has been shown to reduce morning sickness in 1 in 3 women after 6 days (32).
According to a 2014 review which analyzed 12 studies, supplementing with 1.1-1.5 grams of ginger can significantly reduce symptoms of nausea in pregnancy (33).
12Vitamin D is necessary during the 3rd trimester for healthy bones development. A 2006 study showed that while Vitamin D plays many roles in pregnancy, it is best known for assisting to direct and build a healthy skeleton, especially in the third trimester for (34).
If you lack vitamin D during pregnancy, your baby’s health may be compromised. This can put your child at risk for abnormal bone growth, delayed physical development and rickets (which can lead to fractures and deformity). A 2012 study recommends 4000IU vitamin D per day ideal health during pregnancy, above the Institute of Medicine’s recommendation of 200-400IU per day (35).
A 2011 study showed that deficiency of vitamin D has also been linked to a greater risk of developing pregnancy complications such as preeclampsia and gestational diabetes (36).
1Prenatal vitamins may contain vitamin A which is toxic in high amounts, especially for pregnant women. Vitamin A is fat soluble. This means when vitamin A is consumed in large doses it is not easily flushed out of the body, like water-soluble vitamin C. Instead vitamin A is stored in fat cells.
Excessive vitamin A may result in irreversible liver damage, birth defects and cancer(37).
Vitamin A is obtained through the diet in two forms: preformed vitamin A (retinol) and provitamin A carotenoids (like beta-carotene). Beta-carotene appears to be the safer source of vitamin A. The Institute of Medicine of the National Academies’ Food and Nutrition Board recommends against beta-carotene supplements for the general public (38).
The daily recommended intake for pregnancy is 770mcg RAE (retinol activity equivalents) and for lactation, 1300mcg RAE (39).
2Prenatal vitamins may cause nausea. Certain vitamins may cause or worsen nausea when taken on an empty stomach (40). Taking them with food is always a better option.
3Prenatal vitamins may cause constipation. Excess iron can lead to constipation. You can counter this by increasing the amount of dietary fiber you consume and increasing magnesium, an electrolyte that helps regulate stool output and colon contractions.
4Prenatal vitamins may change urine color or odor. B vitamins, in particular, may be the contributing factor, though these are harmless changes.
5Prenatal and other vitamins may lead to excessive intake of nutrients. If your diet is comprised of nutrient-dense, high quality, varied foods, a prenatal multivitamin may be of little need. While toxicity from prenatal vitamins that meet 100% of the recommended daily intake is rare, high dose prenatal multivitamins, especially if combined with other supplements, may lead to excessive nutrient intake and increased risk of complications. A 2010 study found selenium to be 200% higher than the label claimed. Many symptoms were reported including nausea, hair loss and worsened nail health. Caution is advised with supplements because they are not well-regulated. Choose trusted brands that have undergone third-party testing by Consumer Labs or laboratories, or bears the USP verified seal (41).
Recommended Intake & Dosage
To avoid excessive intake, supplements should not exceed the recommended daily amounts. The Institute of Medicine provides the following recommendations (42)
Folate. The recommended intake of folate or folic acid during pregnancy is 600mcg per day (400mcg from supplementation and at least 200mcg from food to ensure adequate intake).
Calcium. 1000mg per day from both food and supplements.
Iron. 27mg per day (see mineral section below if supplementing with iron).
Minerals. With supplemental iron consumption, it’s recommended to have 15 mg of zinc and 2 mg of copper (43).
B12. Only 2.4 micrograms is recommended daily (for those without deficiency or anemia). Many supplements contain far more than the recommended intake which enables you to cut the dose and make the product last longer.
Vitamin D. 400IU to 4000IU per day depending on current vitamin D status, and diagnoses and health history.
DHA/EPA. Next, many prenatal vitamins lack the essential fatty acids you need for optimal brain and nervous system formation in your growing baby, so a quality omega 3 fatty acid supplement containing EFA and DHA is number two here (44).
Probiotics. During pregnancy constipation is more likely and infection is more common due to the body’s naturally lowered immune function (to protect the developing baby). Having probiotics in your system helps to strengthen your immune system, your baby’s immune system, supports regular bowel movements, and increases the chance of your baby having a healthy microbiome (45).
You can start taking a prenatal vitamin during the child-bearing years. A very critical time for your baby’s development is conception through the first 6 weeks, a time which many women are not yet aware they are pregnant.
Note that at any point during your pregnancy is it not too late to begin improving your nutrition and consuming prenatal vitamins.
Even after you have your baby, it is still ideal to continue taking your prenatal supplements to support healthy breastfeeding, which can burn hundreds of calories a day and drain you of as many (or more) nutrients as your third trimester (40).
Is it ok to take prenatal vitamins if you’re not pregnant? You may be tempted to take prenatal vitamins because of unproven claims that they promote thicker hair and stronger nails. However, if you’re not pregnant and not planning to become pregnant, high levels of certain nutrients over an extended period of time may actually be more harmful than helpful.
Do prenatal vitamins make you more fertile? Taking a prenatal vitamin alone probably won’t significantly increase your chances of getting pregnant, though it can help if you have deficiencies in specific nutrients.
Are prenatal vitamins really necessary? Yes, most women can benefit from taking a prenatal vitamin and mineral supplement (preferably before trying to conceive). Think of it as an insurance policy to make sure you’re getting the right amount of certain crucial nutrients during pregnancy.
Why do I feel sick after taking prenatal vitamins? Without food to keep them busy, your stomach acids start to chew on you, a process that, not surprisingly, produces nausea.
Can you have a miscarriage from not taking prenatal vitamins? Prenatal vitamins are usually recommended during a woman’s pregnancy to prevent congenital deformities. The evidence on prenatal vitamins and decreased miscarriage risk has been mixed.
Do prenatal vitamins make you gain weight if you are not pregnant? No vitamin, neither a regular multivitamin nor a prenatal, can make you gain weight. This is because vitamins contain very few calories, and you can’t break them down for energy or store them as fat.
Do prenatal vitamins mess with your hormones? No, research has not shown prenatal vitamins to significantly influence hormones beyond that of vitamin D’s natural (and beneficial) interaction with reproductive hormone production.
Do prenatal vitamins make you poop a lot? Pregnant women need 27 milligrams of iron daily, and many prenatal vitamins contain 30 milligrams. The most common side effect of iron is constipation, but it can also cause diarrhea in some cases. It’s normal if your stools look a bit darker when you start taking a prenatal vitamin but you will not necessarily poop more. If your prenatal vitamin contains fiber or prebiotics, you may notice an increase in stool output.
Do prenatal vitamins mess up your period? There’s no truth to the claim that prenatal vitamins can help regulate your period. Your period depends on hormones released by various body organs, not on vitamins you take.
Do prenatal vitamins make your hair grow faster? The claim that vitamins benefited hair, skin and hair arose because women who usually take prenatal vitamins – that is, pregnant women – naturally have long, thick, fast-growing hair due to pregnancy hormones. While research is limited, deficiency in several nutrients like biotin, omega-3’s, iron and others can affect keratin-rich parts of the body like the nails. If your hair is thinning, nails are brittle or your skin health is poor due to nutrient deficiencies, multivitamins that correct those deficiencies may help.
Being pregnant places a significant strain on your body, which makes sense because you’re supporting yourself AND your growing baby. It’s essential to work with your OBGYN and dietitian to determine the best supplements to support you and your health, your sanity, and your energy.
At the very least it is safe and necessary to include a basic prenatal vitamin, an essential fatty acid supplement, fiber and a probiotic.
This ensures your bases are covered and that you and your baby can thrive during the 9 months of pregnancy.