Which Vitamins Should I Take During Pregnancy?

Which Vitamins to Take During Pregnancy?

25 Doctors Share their Recommendations for Pregnancy Supplements

Written by: Munica Elena

Guest Post by: Taylor Graber MD

Last Updated: October 12th 2021

We were lucky enough to work with Munica Elena on an article she recently wrote, interviewing multiple physicians regarding the benefits of vitamin supplementation in pregnancy. This article was originally published on WeAreFeel.com.

Enjoy!

Pregnancy is a significant time of growth and development and maintaining good health and nutrition throughout is essential to nourish both yourself and your growing baby.

However, even if you’re eating for two, the vitamins and minerals you gain from regular food may not be enough to cover the increased nutrient demands of pregnancy.

The solution? Supplementing with vitamins and minerals specifically formulated to support you and your baby throughout pregnancy.

Minuca Elena reached out to 25 doctors and asked for their opinions on the following questions:

1. Should women take supplements during pregnancy?
2. Which vitamins and minerals do you recommend and what are their benefits?

Of doctors interviewed, 72% recommended supplementing with vitamin D. 68% suggested taking a folate or folic acid supplement, and 60% also discussed supplementing with iron.

Keep reading to find out which vitamins our experts recommend, and why!

Brittany Robles - Postpartum Trainer

I definitely recommend that pregnant women take supplements as it can be difficult to ensure you are getting adequate amounts of each supplement on a daily basis.

The key nutrients I recommend are:

Folate: One of the most important nutrients for pregnancy, as it contributes to the formation of the neural tube and prevents birth defects.
The recommended intake for women pre-pregnancy in 400 mcg per day, starting 3 months before attempting pregnancy.

Vitamin D and Calcium: These nutrients are important for fetal skeletal development.
It’s recommended that pregnant women get 200-600 IU of Vitamin D per day, along with at least 250 mg of calcium.

Iron: Iron is important as it helps with production of red blood cells in mom and placental health in baby. It is recommended that pregnant women take 27 mg daily.

Iodine: Iodine is an essential nutrient for thyroid hormone development. It is recommended that pregnant women take 150 mcg per day, and can also be consumed through dietary sources which include iodized salt.

DHA: DHA is an often-overlooked supplement but is essential for the development of baby’s brain and eyes in utero.
It is recommended that pregnant women take at least 200 mcg per day.

Dr. Jessica Nouhavandi - Honeybee Health

Prenatal vitamins are recommended during pregnancy to ensure the fetus gets what they need.

The following can be found within prenatal vitamins:

Folic acid is a B vitamin necessary for all cellular growth and development. During pregnancy, women need more folic acid than normal for the development and growth of fetal cells. During pregnancy, women should be taking up to 600 mcg of folic acid daily.

Calcium helps the fetus’ bones, teeth, muscles, and nerves develop. During pregnancy, 1,000 mg of calcium is needed daily.

Vitamin D is required to help the body’s nerves, muscles, and immune system function. During pregnancy, 600 IU of vitamin D is needed daily.

Iron is used to make hemoglobin, and protein which help carry oxygen around the body, and it’s recommended that pregnant women take 27 mg iron daily.

Iodine is also required during pregnancy to help develop the fetus’ nervous system, supporting movement and cognition. 220 mcg of iodine is recommended daily.

Alaina Brinley Rajagopal - The Emergency Docs

Every woman should be taking a prenatal vitamin during pregnancy along with following a healthy diet.

The recommended supplement is a prenatal vitamin with folic acid, iron, calcium, vitamin D, choline, omega-3 fatty acids, B vitamins, and vitamin C. Your obstetrician can recommend a specific vitamin or suggest additional supplements as needed.

The supplement should contain at least 400 mcg of folic acid to help meet the 600 mcg of folic acid needed per day for pregnant women. Folic acid is important to prevent certain birth defects, and you should begin taking folate at least one month before you start trying to get pregnant and continue throughout the pregnancy.
Folic acid can also be found in foods including leafy green vegetables, fortified cereal, enriched bread and pasta, peanuts, orange juice, and beans.

Our Feel Pregnancy contains 25 mcg vitamin D3 (as Cholecalciferol from algae), providing 250% of the recommended daily vitamin D3 intake for women during pregnancy1.

Mark Trolice - My Fertility Care

Folic acid: Many pregnant women worry about the risk of birth defects, but this risk can be significantly reduced through supplementing with folic acid.
Pregnant women should aim for a folic acid intake of 600 mcg daily. Folic acid supplementation can start before pregnancy, as it may improve fertility rate, and continue throughout pregnancy.

Iron: Iron is vital to carry oxygen to the growing foetus, and women require almost double the amount when they are pregnant! Most pregnancy vitamins contain the recommended amount: 27 mg.
My tip for iron rich foods: lean red meat, fish, poultry, dried beans and peas, prune juice, and iron fortified cereals.

Calcium: The growing foetus needs support for bones and teeth, so pregnant women should be supplementing with 1,000 mg of calcium every day.
Great food sources of calcium include: dairy products, sardines, broccoli, and dark leafy greens.

Vitamin D: Like calcium, vitamin D supports the development of bones and teeth, and is also vital for healthy skin and vision. All women need 600 IU of vitamin D a day, either from vitamins or dietary sources such as fortified milk or fatty fish like salmon. Sun exposure is also important as it converts a chemical in the skin to vitamin D.

DHA: DHA, or docosahexaenoic acid, helps with growth and development of baby’s brain and eyes. Not all prenantal vitamins contain DHA so good sources include: fish that are low in mercury, including herring, salmon, trout, anchovies, and halibut; orange juice, milk, and eggs.

Iodine: Iodine helps the body produce thyroid hormone and supports the development of baby’s brain and nervous system. Good sources include: fish, dairy products, fortified cereal and bread, and iodized salt.

Carrie Lam - Dr. Lam Coaching

Women should take prenatal vitamin supplements before and during pregnancy as nutrient intake needs increase when pregnant.

Certain supplements are safe during pregnancy:

Vitamin B6 can be safely taken when feeling nauseated especially during the first trimester, and folic acid is especially important during pregnancy to help prevent neural tube defects.

Vitamin D can also be supplemented safely if one stays mostly indoors and doesn't get enough sunlight.

If one is suffering from anemia, then iron can be taken safely to help boost blood levels.

Feel pregnancy contains 400 mcg body-ready folic acid (folate) providing 100% of the recommended daily folic acid intake for women during pregnancy2, to help prevent birth defects.

Dr. Ng Kai Lyn - Gynae Patient Info

Requirements for certain nutrients are significantly higher during pregnancy compared to the non-pregnant state, and many women are advised to take supplements.

Here is a useful list of essential vitamins and minerals to include in your diet:

Folic acid: A dose of at least 400 micrograms daily should be started 3 months before you get pregnant and throughout your first three months of pregnancy. This helps prevent neural tube defects in your baby.

Calcium: Increase your calcium intake to boost the formation of strong bones and teeth for your baby.
Good calcium sources of calcium include milk, cheese, yogurt, and green leafy vegetables. You may take oral supplements available over the counter.

Vitamin D: should be paired with calcium as it is required for absorption. Food sources include fortified milk, cold water deep-sea fishes, and butter.
Getting out in the sun helps you make vitamin D too! Vitamin D is commonly added in your calcium and prenatal supplements so keep a lookout for it.

Iron: this is essential in the formation of red blood cells for both you and your baby. Insufficient iron in the body causes anemia – this can result in giddiness, fainting, tiredness, or even shortness of breath and chest pain in severe cases.
Aim to take vitamin C with iron rich foods to enhance absorption. Remember not to take your iron supplements within 2 hours of calcium supplements due to absorption interference.

Omega-3 Fatty Acid (DHA): This is vital for your baby’s brain and eye development. Although DHA is found in deep sea fishes, avoid fishes with high mercury levels. DHA-rich sources that are safe include salmon, sardines, herring, halibut and omega-3 fortified eggs. You can also obtain your source of DHA from oral supplements – including vegetarian options – which are easily available.

Every woman (and her pregnancy) can be different in their unique ways so remember to check with your OB-GYN to ensure you’re taking the right supplements.

Dr. Danielle Plummer - HGPharmacist

Pregnant women should take supplements if they have any nutrient deficiencies or if higher doses of nutrients are required during pregnancy.

All women should take 0.4 - 0.8 mg of folic acid daily starting at least one month prior to pregnancy through 12 weeks to lower the risk of developing neural tube defects. If they have a family history of neural tube defects, they should supplement with 4 mg/day. The methylated form, methyl folate can be taken if they have a variation of the MTHFR gene mutation.

Vitamin B12 (Hydroxycobalamin, Cyanocobalamin, Methylcobalamin) is also important in working with folic acid to develop a healthy nervous system.

Important supplements include vitamin B1 (Thiamine), at least 100mg, to prevent complications including Wernicke’s Encephalopathy and vitamin B6 (Pyridoxine) to decrease nausea.

Magnesium and potassium may help women experiencing muscle cramps or restless legs and vitamin K may help women with clotting disorders. As most of us are deficient in vitamin D, supplementing may be necessary to increase immunity and bone strength. Women with mild nausea may also benefit from ginger. Women with severe nausea and vomiting quickly become depleted in vital nutrition and may need supplementation through alternative routes.

Dr. William Haas - OvulifeMD

Despite our best efforts to eat clean and stick to a balanced diet, many women in the United States have deficiencies in some key vitamins and minerals required for pregnancy.
Because the baby gets all necessary nutrients from the mother, more of these essential vitamins and minerals are required during pregnancy.

The American College of Obstetrics and Gynecologists specifically recommends getting adequate amounts of 10 different vitamins and minerals: calcium, iron, choline, vitamin A, vitamin C, vitamin D, vitamin B6, vitamin B12, and folic acid. These nutrients help with everything from brain development to bone growth. Folic acid is especially important for preventing birth defects of the brain and spinal cord - that’s why it’s found in nearly every prenatal vitamin.

Some of the recommended vitamins, such as choline, are not as commonly found in prenatals, so it’s important to take a close look at the label and review the specific one you're taking with your OB/GYN.

Our Feel pregnancy provides a complete range of B vitamins with health benefits including support for a heathy functioning nervous system, reduction of tiredness and fatigue, and supported energy release from food.

Dr. Lawrence Gerlis - Same Day Doctor

When one considers that a full new human life has to develop within the space of nine months, it is easy to recognize the substantial nutritional requirements to sustain this development.

Alongside extra calorie requirements, certain vitamins and minerals are considered very important, and therefore an entire range of vitamins and minerals should be supplemented during pregnancy. In particular; vitamins B6 and B12, as well as A, C, D, and K.

Minerals are also important, and magnesium, calcium, and zinc should all be supplemented.

Iron supplementation is important as the new fetus demands a lot of iron, and iron deficiency anemia is very common in pregnancy, particularly in those on vegan and vegetarian diets. Regular blood tests are important to assess iron status and detect vitamin deficiencies in advance.

Folic acid deficiency in particular may be associated with fetal abnormalities.

Dr. Kate Killoran - Your Doctors Online

Adequate nutrition is vital to a healthy pregnancy and obtaining most nutrients from your diet is the best way to absorb necessary vitamins and minerals.

Often, the need for nutrients increases beyond what we can deliver through food during pregnancy, and therefore, a prenatal vitamin is recommended.

Some of these important vitamins and minerals include folic acid, iron, calcium, vitamin D, choline, omega-3 fatty acids, B vitamins, and vitamin C.

For many women, eating a nutritious diet and a prenatal vitamin is sufficient, but there are several circumstances where additional folate is recommended, including diabetes, smokers, certain medications, or history of a neural tube defect.

Other supplements that are safe and may have benefits include ginger for nausea, fish oil for brain development and depression, and choline, which is an important nutrient with benefits including brain development, fetal and placental growth, and reduction in chronic disease. Many prenatal vitamins may not contain choline and thus an additional supplement may be necessary.

Choline is not commonly found in prenatal supplements, despite having a key structural role in cell membranes and nerves required for fetal growth and brain development. 

Dr. Kristin Saxena - Saxena Family Foundation

It is recommended that pregnant women take a daily prenatal vitamin. Pregnancy increases the need for nutrients and, while these are best derived from the diet, a good prenatal vitamin helps ensure these needs are being met.

One of the most important nutrients to look for in a prenatal vitamin is folic acid. It is recommended that pregnant women take at least 600 mcg of folic acid per day to reduce the risk of neural tube defects and congenital abnormalities like cleft palate or heart defects.

It is also good to look for a prenatal vitamin that contains the essential fatty acids DHA and EPA which appear to be correlated with improving a baby’s brain development and possibly reducing maternal depression.
Additional supplements may be suggested by your doctor such as iron if you are experiencing pregnancy-induced anemia.

Other supplements such as additional vitamin D, magnesium, and probiotics are likely to be safe and may be beneficial, however, it is imperative that women always check with their health care professional before starting any new supplement because supplements are not regulated by the Food and Drug Administration and most have not been studied well in pregnant women.

Dr. Mubashar Rehman - HealthCreeds

In theory, with proper nutrition, vitamin and mineral supplements are not necessary. In practice, many doctors recommend them.

The mother's body needs to compensate for the vitamins and minerals consumed by the new life that is forming. For this reason, doctors recommend that pregnant women take the following vitamin supplements:

Folic acid: several studies have shown that additional folic acid intake helps reduce the risk of congenital malformations of the neural tube, an embryonic structure that forms the brain and spinal cord.

Omega-3: some studies suggest that the development of a baby's eyesight and nervous system may be helped by the consumption of omega-3 fatty acids.

Iron: Iron is necessary for the regeneration of haemoglobin, the oxygen-carrying component of the blood. Some women may have low iron levels leading to anaemia. That is quite common in pregnancy because the extra fluid content in the blood dilutes the amount of circulating iron, and the baby also uses some of the mother's reserves.

Calcium: since the calcium requirements of a developing baby are high, the idea is to increase the calcium intake to prevent decalcification of bones and teeth in the mother.

Vitamin D: Many calcium supplements nowadays include vitamin D, since it helps the proper absorption of this mineral and, therefore, it is important for the correct formation of bones.

Tracy Lyon - Children’s Hospital of San Antonio

It is recommended that women take a prenatal vitamin starting at least 3 months prior to attempting to conceive, or if they are sexually active and not using any contraception.

A prenatal vitamin, and not a multivitamin, is preferred as prenatal vitamins have the correct dosages of vitamins and minerals recommended for the average pregnant patient.

It is recommended that women take 400 mcg of folic acid per day to prevent Spina Bifida. Spina bifida can result in a baby never being able to walk and has been determined at about the time you have a positive pregnancy test. Starting a prenatal vitamin after you become pregnant is too late to prevent this condition.

Women should NOT take over 10,000 I.U. of Vitamin A per day. Some multivitamins exceed this amount and can result in birth defects.

Vitamin D is not routinely supplemented, but if a woman knows she has low Vitamin D levels, she should take 600 – 2,000 I.U. per day. Low levels of Vitamin D during pregnancy have been associated with skeletal issues in the baby.

There are no other vitamins routinely recommended during pregnancy, but fish oil or Omega-3 fatty acids may help to prevent premature labour, preeclampsia and postpartum depression.

Having a healthy diet including intake of fruits, vegetables and other foods that provide B vitamins, calcium and iron can also have a positive impact on a pregnancy.

Dr. Jacky Montoya - Vitaya MD

Women should begin supplementing prior to pregnancy, continue throughout, and also during post-partum. Supplementation is essential as it ensures necessary vitamins are available in abundance and that the woman and baby’s health is not being compromised.

During pregnancy, a woman’s body undergoes many physiological changes, and the body is quickly and readily adapting. It is important that women have a well-rounded and nutritious diet during pregnancy to ensure the body has everything it needs to grow a beautiful baby.

The most important vitamins include folic acid, calcium, iron, iodine, vitamin D, and a combination of the B vitamins.

Folic acid is necessary to avoid neural tube defects in the first 12 weeks of pregnancy. Foods that include folic acid are leafy vegetables, beans and nuts.

Calcium is another important mineral that the baby needs to grow; as the mother’s calcium becomes depleted, she risks losing bone density during pregnancy.

Iodine is very important to maintain thyroid function, and iron is important in producing and replenishing blood cells needed to carry oxygen and nutrients to the baby.

The easiest way to approach nutrition during pregnancy is to think: ‘everything I put in my mouth should provide some nutritional value to the baby’ and occasional cravings can be satisfied knowing most of your intake is nutritious and provides valuable vitamins and minerals.

Preconception, Iodine is a key mineral for fertility, and previous studies have linked iodine deficiency with reduced fertility.

Dr. Shaista Waheed - Healthwire

During pregnancy, fetal growth depends completely on nutrients coming from the mother. Many important nutrients are known to support placental development.

Here’s why pregnant women need to consume DHA supplements:

DHA (docosahexaenoic acid) is an essential structural fatty acid required for retinal and central nervous system development in children. Most brain development is completed during pregnancy, requiring support from maternal nutrition.

Normally, omega-3 is metabolically converted into DHA, however during pregnancy, there is a reduction in the metabolic processing of this fatty acid.

Consequently, in order to support baby’s brain and retinal development, women need to supplement with DHA during pregnancy, alongside consuming a DHA-rich diet.

***Dr. Taylor Graber - ASAP IVs

Pregnancy-induced morning sickness with nausea and vomiting is extremely common.

Vitamin B6 has been shown to be helpful with mild-moderate nausea levels, and although the direct mechanism is not known, maternal levels of B6 naturally decrease throughout pregnancy. The supplement dose of vitamin B6 is 10-25 mg every 6-8 hours as tolerated, up to a maximum of 200 mg per day. Taken as a supplement, vitamin B6 has an excellent safety profile, minimal side effects, and is easily available as an over-the-counter supplement.

Dr. Madathupalayam Madhankumar - iCliniq

Consuming the right nutrients is vital at every stage of life, but especially during pregnancy in order to nourish both yourself and the growing etus.

Experts from the American College of Obstetrics and Gynecology recommend that all pregnant women take a prenatal vitamin and folic acid supplement to fill the nutritional gaps and prevent developmental abnormalities at birth. Prenatal vitamins are multivitamins which meet the increased demands for micronutrients during pregnancy.

Folate is a vitamin that plays a major role in DNA synthesis, red blood cell production, and the development of the fetus.

Iron is vital for oxygen transport and the healthy growth and development of your baby and the placenta.

Vitamin D is a fat-soluble vitamin for better immune function, bone health, and cell division.

Dr. Ashley Margeson - Superwoman Code

There are 3 key supplements indicated in pregnancy:

The first is Folate, a B vitamin shown to dramatically reduce the risk of neural tube defects during development. We recommend taking folate if there is even a chance of pregnancy.
I also recommend iron and omega-3 based on bloodwork and symptoms.
Bloodwork for both hemoglobin and ferritin can indicate whether iron supplementation is necessary. If so, an easily absorbable iron such as heme-iron reduces the risk of concentration.
‘Baby brain’ can start to appear in the second or third trimester, indicating that omega-3 fatty acid is generally necessary.

Dr. Burt Webb - Vitalitymds

Women should take supplements during pregnancy, but more importantly, they should be taking supplements before they become pregnant.
Many women don’t feel well during pregnancy and therefore do not take supplements on a regular basis.

Most prenatal vitamins are also poor quality, raising questions about how and if the nutrients are absorbed. Pharmaceutical grade supplements have much higher standards regarding their purity and absorption levels than most prenatal vitamins.

Dr. Kecia Gaither - Dr. Kecia Gaither

Women should take supplements during pregnancy, and in particular, I always recommend vitamin D.

Vitamin D is essential for cardiovascular and brain health, as well as acting as an immunity booster, which is essential for mom and baby during pregnancy. Vitamin D also decreases the incidence of preterm labor.

Vitamin D is produced in the skin in conjunction with sunlight and is beneficial to bone development. As melanin inhibits vitamin D production, individuals of color are at increased risk of vitamin D deficiency, making it increasingly important for women of color to supplement with vitamin D during pregnancy. It’s generally recommended to take between 1000-2000 IU daily.

Dr. Tamika Cross - Dr. Tamika Cross

I don’t really recommend anything outside of prenatal supplements, so I would say no. It’s better to have a well-balanced diet, and a lot of things you can get from a well-balanced diet. The point of supplements is to supplement things we are not taking in in our diet.

I definitely don’t necessarily recommend anything else because the focus should be on a well-balanced diet focusing on proteins, carbs, fat, foods which are rich in iron, and folic acid.

Usually in pregnancy I recommend prenatal vitamins as they can give more of a boost than the average western diet. There are so many different brands so grab whichever ones you feel comfortable with, whether it’s gummies, pills, whatever. As long as they have DHA in them, which lots of them do, it’s fine.

I just wouldn’t do the other supplements, because people take the ones on the market and then end up taking an excessive amount of vitamins that can actually be toxic.

If you have too much vitamin A of vitamin C, that can be bad for the baby, so I definitely don’t recommend taking additional supplements.

Dr. Alan Lindemann - Dr. Alan Lindemann

During pregnancy, women should take prenatal vitamins as suggested by their physician.

My first practice was in a rural Minnesota community surrounded by farms. In my first 6 months, I had two patients deliver babies with neural tube defects. I considered this a high incidence and thought it may be something in the environment. Later the connection between low folic acid intake and neural tube defects was made.
Prenatal vitamins should contain 400 mcg folic acid, continuing this level of folic acid pre-conception and throughout pregnancy.

Iron is also important to consider. Due to an increase in blood during pregnancy, individuals can develop anemia. Iron is needed to form hemoglobin, and it takes around 3 months for the body to produce enough blood cells and for hemoglobin levels to increase in-line with the increase in blood volume.
However, iron supplements can make you nauseated and constipated, so it can help to eat before taking prenatal vitamins.

Allie Edwards - The Perfect Pregnancy Plan

Women should absolutely take supplements during pregnancy, however it’s important that they know what to take, how much, and that they are getting the highest quality supplements possible.
In recent years we have learned that prenatal nutrition is obscenely more important than previously realized.

It is now known that what you eat actually changes how your baby’s genes are expressed, essentially meaning that you have the power to ‘switch on’ good genes and ‘switch off’ bad genes based on diet and activities during pregnancy.

The only prenatal nutrition and fitness program that explains this in detail and how to apply it is called The Perfect Pregnancy Plan and is based on the most up to date scientific research.

While it’s ideal to get the bulk of nutrients during pregnancy from your diet, some of the nutritional requirements for optimal fetal growth and development are so high that supplementation is essential.

Always make sure to check where your supplements are sourced, do your research, and aim for ‘as close to nature’ as possible.

Dr. Mona Fahoum - Meridian Medicine

We see a number of women who have histories of chronic vaginitis and sexual dysfunction and there are ways to restore vaginal health with herbal medication and pharmaceuticals when appropriate.
When the body is not happy there can be a substance or chronic inflammation environment for the fertility of ovulation, which can be supported through adaptogenic supplements that balance hormone levels.
A strong multivitamin can support balanced nutrient levels. Nutrients to watch include vitamin D, zinc with copper (long-term zinc can deplete copper) and vitamin C. Natural antioxidants can be consumed by eating berries!

Let an expert help: working with alternative, functional and integrative doctors can be helpful long-term, pre and post fertility.

Fadwah Halaby - Midwife360

We do recommend supplements, but only if the client believes they are unable to get all required nutrients from food. Diet should be the number 1 source of nutrients, whether pregnant or not. If a person wants to take a pre-natal vitamin or supplements, we always recommend a food-based option to increase absorption by the body; many synthesised vitamins and minerals pass through the body unabsorbed.
Many individuals are deficient in vitamin D, and even if they are in the normal range are not likely to be high enough in the range for the effects to be health protective.

Magnesium is another great supplement for pregnancy, as it can help with sleep, constipation, muscle soreness, high blood pressure, and pre-term contractions.

Probiotics are also an essential part of a healthy lifestyle. Having a robust digestive system with the ability to break down food and assist the body with nutrient absorption is the foundation of healthy living.

Herbal teas or infusions can also be used to support nutrient intake as needed.

Thank you to all the medical experts who contributed to this expert roundup! If you enjoyed reading this post, please share it on social media with your friends and family.

[This post is meant to inform. Before taking any new supplements, it’s best to refer to your doctor for advice on doses, safety, and potential risks and benefits.]

References

1. Vitamin D in Pregnancy (Scientific Impact Paper no. 43) - https://www.rcog.org.uk/en/guidelines-research-services/guidelines/sip43/

2. Nutrient Intake Values for Folate During Pregnancy - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3820052/

3. UK Government Dietary recommendations for Energy and Nutrients - https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/618167/government_dietary_recommendations.pdf

4. UK Guidelines on the Management of Iron Deficiency in Pregnancy - https://onlinelibrary.wiley.com/doi/full/10.1111/bjh.16221

5. Healthy Eating and Vitamin Supplements in Pregnancy - https://www.rcog.org.uk/globalassets/documents/patients/patient-information-leaflets/pregnancy/pi-healthy-eating-and-vitamin-supplements-in-pregnancy.pdf

6. A review of the iodine status of UK pregnant women and its implications for the offspring - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4442695/