US Pharm. 2013;38(9):12-15.
Prenatal supplements are a critical component of health
care during pregnancy. Pregnant patients may ask the pharmacist if these
supplements are necessary and request information on specific
nutrients. Pharmacists should be aware of the vitamins and minerals that
are most important during pregnancy and be able to offer advice on
other dietary supplements that may be harmful to a developing fetus.
Necessity for Prenatal Supplements
Patients may ask pharmacists whether there is an actual
need to take prenatal supplements. Various governmental Web sites offer
justifications for taking prenatal supplements, presenting them in terms
pharmacists can use when explaining the issue to pregnant patients.1,2
When doing so, pharmacists can refute several misconceptions. One is
that a normal, healthy diet can meet the nutritional needs during
pregnancy. Patients should be told that this view is incorrect because
their needs for nutrients during pregnancy change remarkably, making it
extremely difficult to meet those needs through diet alone. Another
fallacy is that standard vitamin/mineral supplements are just as
effective as prenatal supplements and that pregnant women can simply
continue their intake of those standard supplements.
Pharmacists can counter these misconceptions by urging
pregnant patients to begin to think of the growing fetus as an
individual with its own needs for proper nutrition. These needs make
standard supplements suboptimal. A final misbelief is that a woman can
wait until she knows she is pregnant to take pre-natal supplements. The
need for folic acid invalidates this idea.
Folic acid/folate is one of the B vitamins, a group of water-soluble nutrients that meets critical needs.3-8
It is found in various vegetables (especially dark green, leafy
varieties), such as spinach, asparagus, Brussels sprouts, romaine
lettuce, avocado, okra, and broccoli, and also in nuts, dairy products,
poultry, bananas, melons, eggs, seafood, beans and peas (green peas,
black-eyed peas), citrus fruits and their juices (e.g., lemons,
oranges), most berries, whole grains, and beef liver. The FDA required
manufacturers to add folate to foods in January 1998.8 As a
result, folate is now found in enriched breads, fortified breakfast
cereals, flour, cornmeal, pasta, rice, and other grain products.
Deficiency of folate is not common and seldom occurs as an isolated deficiency.3
Rather, it is usually indicative of an overall poor diet and, as such,
often coexists with other vitamin and mineral deficiencies. Such overall
deficiencies are caused by chronic alcoholism, poverty, fad diets, and
In a 2003-2006 U.S. study, investigators discovered that
the effects of folate supplementation were so successful that most
people do obtain sufficient folate from diet. Typical daily intakes
ranged from 454 to 652 mcg of DFE (dietary folate equivalents) for
adults and 385 to 674 mcg in children aged
1 to 18 years.3
Despite the encouraging results of the national study,
some groups were found to have lower intakes of folate. They included
women of childbearing age and non-Hispanic black women. Suboptimal
levels were found in 19% of 14- to 18-year-old females and 17% of women
aged 19 to 30 years. While 13% of non-Hispanic white women had
suboptimal intakes, a full 23% of non-Hispanic black women did not
achieve optimal intake.3
Folate is of such importance due to its role in the
prevention of neural tube defects (NTDs). These are a group of birth
anomalies that involve the spine, skull, and brain, with the most common
being spina bifida and anencephaly.3,7 With spina bifida,
the fetal spinal column fails to close at either the upper or lower end,
which usually occurs at 21 to 28 days following conception. As a
result, the spinal cord is not protected. Unfortunately, the nerves that
control legs and other functions fail to work appropriately, leading to
a need for surgeries and probable disability. Anencephaly is a lethal
defect in which the brain does not develop or develops incompletely.
Babies with anencephaly usually expire before or shortly after their
NTDs affect 3,000 infants annually in the United States.8 The risk of spina bifida and anencephaly is highest among Hispanic women and lowest among African Americans and Asians.3 If women ingest sufficient folic acid, the risk of NTDs drops by 50% to 70%.8
The compelling nature of this finding caused the U.S. Public Health
Service and the Institute of Medicine both to recommend that all women
capable of becoming pregnant consume 400 mcg of folic acid daily through
use of supplements, fortified foods, and a diet containing folate-rich
Many pregnant women do not ingest sufficient calcium for a
number of reasons. First, some think of calcium only in relation to
preventing osteoporosis in the older female. Because of this
misperception, many younger women have not established the habit of
ingesting daily calcium supplements. Second, teenaged mothers are still
in the process of developing their own bone mass, increasing the need
for calcium supplementation beyond that of the pregnancy itself.9 Third, the woman may ingest a suboptimal amount of calcium, thinking it is sufficient.
These misconceptions can wreak havoc with the growing fetus and its mother.10 The infant must have sufficient calcium to develop normal bone and teeth, requiring a total of 30 g by delivery.11,12 The last trimester is the most critical period, as 80% of the fetal skeleton develops during this time.12 Should maternal calcium intake be sub-optimal, the body will divert bone from the mother’s skeleton to meet fetal needs.
Women who do not ingest sufficient calcium are somewhat protected due to normal human responses to pregnancy.11
Pregnant women experience an enhanced ability to absorb calcium, both
from foods and supplements, a response that strengthens during the
second half of the pregnancy. Enhanced estrogen levels during pregnancy
also protect bone density. Furthermore, most females quickly replace
pregnancy-related bone loss after they cease breastfeeding.
However, experts still advise supplemental calcium during
pregnancy to help ensure that the needs of the growing fetus will not
compromise the woman’s calcium status, predisposing her to osteoporosis
in later life. The U.S. Food and Nutrition Board established the
recommended daily amount of calcium as 1,300 mg for pregnant females
aged 14 to 18 years and 1,000 mg for those aged 19 to 50 years.9
Recommended dietary sources of calcium include low-fat dairy products
(e.g., milk, yogurt, cheese, ice cream); dark green, leafy vegetables
(e.g., broccoli, collard greens, bok choy); almonds; tofu; corn
tortillas; and calcium-fortified foods (e.g., orange juices, breads,
The two main calcium supple-ments are carbonate and
citrate. Calcium carbonate requires an acidic environment for
absorption, so it should be taken with food.9 On the other
hand, calcium citrate is absorbed well regardless of stomach pH, making
it more convenient for all patients, and a better therapeutic choice for
pregnant women with achlorhydria, inflammatory bowel disease, and
absorption disorders. Patients also report that calcium citrate is less
constipating than carbonate. Unfortunately, most prenatal supplements
contain calcium as the carbonate salt. If this is problematic, patients
might be urged to consult their obstetrician about choosing a
calcium-free prenatal supplement and ingesting calcium citrate (e.g.,
Citracal) as a separate supplement.
Iron is located inside the hemoglobin within our red blood
cells. It ensures an adequate oxygen supply to our organs and tissues.13-16 It also is responsible for carrying carbon dioxide waste back to the lungs to be exhaled.15 Iron can be found in most meats, particularly liver and beef products.13,15,16 These generally contain a more readily absorbed form of iron referred to as heme iron.16
Certain green, leafy vegetables (e.g., spinach) and herbs such as
parsley are also high in iron. Fortified foods can also be good sources
of iron and include many types of cereal.13-16 Vegetables and fortified foods contain nonheme iron, which is not absorbed as easily.16 Meat proteins and vitamin C have been shown to increase absorption of nonheme iron when consumed with nonheme iron products.16
A deficiency in iron can lead to a condition known as iron deficiency anemia, or IDA.14 IDA is the world’s most common nutritional deficiency.17,18
Furthermore, as many as half of pregnant women may experience IDA due
to a higher volume of blood during pregnancy, a growing fetus, and
eventually blood loss during delivery of the infant.14 Pregnant women who have IDA experience a higher incidence of premature labor and low birth weight newborns.13,16,19,20
The recommended dietary allowance of iron for pregnant women is 27 mg daily.1,14-16,18
Although it is possible to supplement this with dietary changes, many
patients choose to use one of the available oral OTC iron products. The
preferred salt forms are either ferrous sulfate or ferrous gluconate due
to their lower cost and higher bioavailability than other products.21 Adverse effects commonly seen with iron supplementation can include nausea, vomiting, constipation, and diarrhea.14
Certain products such as those containing polysaccharide-iron complex
claim to have fewer side effects than others, but there is no reliable
evidence to support this. Other products are enteric coated, which can
reduce some of the nausea observed. However, these products do have
decreased absorption. It is possible to take food with the supplement to
decrease stomach upset, but this can lower absorption by up to 40% to
50%.15 It is important to be tested for anemia at the first prenatal visit to ensure supple-mentation is necessary.14
Other medications have the potential to inhibit iron
absorption. Because calcium is also a vital supplement during pregnancy,
it is important to note that calcium can interfere with the absorption
of iron. This includes foods high in calcium such as dairy products. The
patient can remedy this by separating the intake of calcium and iron.15 As many as 50% of pregnant women also can experience gastroesophageal reflux disease (GERD) during pregnancy.22
These patients may take antacids or drugs used to treat this condition,
and all of these can interact with the absorption of iron.18
Pregnant patients also may have other children in the
house; therefore, it is pertinent to inform each patient of the dangers
of keeping iron within reach of children. As low as 60 mg/kg can be
deadly, and single fatal doses of 200 mg have also been reported.14,15 Other complications include liver failure and severe hypotension.15
Patients should be informed to keep bottles tightly capped and away
from children’s reach. If at any point excessive iron consumption is
suspected, a doctor’s appointment, emergency room visit, or call to a
Poison Control Center is warranted.
What To Do Before You Are Pregnant
Experts offer a set of instructions that are most important to follow if you plan to become pregnant:
1) Folic acid has been found to be extremely important in
reducing the risk of birth defects of the brain and spine. However, you
cannot wait until you know you are pregnant to take it, as that is too
late. You should take 400 to 800 mcg of folic acid every day for a full 3
months before you even try to become pregnant. This is simple and
2) Smoking and drinking during pregnancy can have
devastating effects on a growing fetus. For this reason, you must stop
all use of alcohol and tobacco products (including cigarettes and all
forms of smokeless tobacco) before you even become pregnant. Stopping
these unhealthy addictions before pregnancy helps you undergo the 9
months of pregnancy without exposing your fetus to these toxic
chemicals. Your physician can help with cessation.
3) Halt use of any homeopathic remedies, herbs, and
dietary supplements, except for prenatal supplements. None are proven
safe and effective for any medical use, and using them during pregnancy
could be dangerous to you and your fetus.
4) Be sure to follow all medical advice in order to keep
any health conditions you might have under control, including diabetes,
asthma, obesity, hypertension, thyroid disease, depression, and
epilepsy. Get all suggested vaccinations.
5) Medications that you ingest can be harmful to a fetus.
See a physician for advice regarding any drugs you must take regularly
for a medical condition. There may be safer alternatives. Include OTC
products in your list, even vitamins and minerals.
6) Stay away from any toxic substance or material at work
and at home. Stop use of or contact with chemicals and do not touch cat
or rodent fecal material.
After You Become Pregnant
Read the instructions in the above paragraphs and do your
best to comply with them during your pregnancy. You must now also obtain
prenatal care. Prenatal care is defined as the preventive medical care
you require when you are pregnant. It is vitally important to make a
physician appointment as soon as you realize you are pregnant. The
sooner, the better. Research has shown that babies whose mothers do not
get prenatal care are three times more likely to have a low birth weight
and five times more likely to die.
In addition, when you choose a physician, make that doctor
a regular part of your life. List all of the medications you take at
your first appointment and ask your doctor’s advice on what to do about
them. You will be scheduled for many repeat appointments to check your
health and that of your growing fetus. Be sure to keep those
appointments. Your doctor and caregivers will provide numerous
instructions to help maximize the health of your child. Follow all of
the advice as closely as you possibly can to ensure a healthy pregnancy.
Remember, if you have questions, Consult Your Pharmacist.
1. Why take a prenatal supplement? U.S. Department of
Accessed July 27, 2013.
2. Prenatal care fact sheet. U.S. Department of Health and
Human Services (HHS).
Accessed July 27, 2013.
3. Dietary supplement fact sheet: folate. Office of
July 27, 2013.
4. Food safety for moms-to-be: before you’re
pregnant—folic acid. FDA.
July 27, 2013.
5. Folic acid. Recommendations. CDC. www.cdc.gov/ncbddd/folicacid/recommendations.html. Accessed July 27, 2013.
6. Folic acid. MedlinePlus. www.nlm.nih.gov/medlineplus/druginfo/natural/1017.html. Accessed July 27, 2013.
7. Folic acid fact sheet. Office on Women’s Health.
Accessed July 27, 2013.
8. CDC. Use of vitamins containing folic acid among women of childbearing age—United States, 2004. CDC. MMWR. 2004;53:847-850. www.cdc.gov/mmwr/preview/mmwrhtml/mm5336a6.htm. Accessed July 27, 2013.
9. Dietary supplement fact sheet: calcium. Office of
July 27, 2013.
10. Mahadevan S, Kumaravel V, Bharath R. Calcium and bone disorders in pregnancy. Indian J Endocrinol Metab. 2012;16:358-363.
11. Pregnancy, breastfeeding, and bone health. NIH
Osteoporosis and Related Bone Diseases National Resource Center.
Accessed July 28, 2013.
12. Heringhausen J, Montgomery KS. Maternal calcium intake and metabolism during pregnancy and lactation. J Perinat Educ. 2005;14:52-57.
13. Pregnancy: Does every pregnant woman need daily iron supplements, and what are the possible adverse effects? PubMed Health. www.ncbi.nlm.nih.gov/pubmedhealth/PMH0005105/. Accessed July 26, 2013.
14. Anemia fact sheet. Office on Women’s Health.
Accessed July 26, 2013.
15. Iron. MedlinePlus. www.nlm.nih.gov/medlineplus/druginfo/natural/912.html. Accessed July 26, 2013.
16. Dietary supplement fact sheet: iron. Office of Dietary
Accessed July 22, 2013.
17. Krafft A, Murray-Kolb L, Milman N. Anemia and iron deficiency in pregnancy. J Pregnancy. 2012;2012:241869.
18. Iron and iron deficiency. CDC. www.cdc.gov/nutrition/everyone/basics/vitamins/iron.html. Accessed July 22, 2013.
19. Pena-Rosas JP, De-Regil LM, Dowswell T, Viteri FE. Daily oral iron supplementation during pregnancy. Cochrane Database Syst Rev. 2012;12:CD004736.
20. Preidt R. Iron supplements may prevent anemia during pregnancy. MedlinePlus HealthDay. June 21, 2013. www.nlm.nih.gov/medlineplus/news/fullstory_138048.html. Accessed July 22, 2013.
21. Gautam CS, Saha L, Saha PK, Sekhri K. Iron deficiency
in pregnancy and the rationality of iron supplements prescribed during
pregnancy. Medscape J Med. 2008;10:283. www.ncbi.nlm.nih.gov/pmc/articles/PMC2644004/. Accessed July 26, 2013.
22. Malfertheiner SF, Malfertheiner MV, Kropf S, et al. A
prospective longitudinal cohort study: evolution of GERD symptoms during
the course of pregnancy. BMC Gastroenterol. 2012;12:131.
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