Targeted, individualised nutritional therapy may be the best way to keep pregnant women healthy. [Photo: Bigstock]

Are supplements in pregnancy ‘unnecessary’?

26 July, 2016

During pregnancy you may find that you are more acutely aware of the potential risks to your baby of taking even so much as a decongestant or an indigestion tablet.

Given this many women who feel the need for a safe alternative which can produce long-term results, turn to natural medicine to deal with everyday symptoms and to nutritional medicine – supplements and a healthy diet – to ensure a healthy pregnancy and a healthy baby.

So what are we to make of a recent review of vitamin supplements in pregnancy in the journal Drug and Therapeutics Bulletin, which suggested that most prenatal supplements were a waste of money? According to the report – whose authors remained mysteriously anonymous: “For most women who are planning to become pregnant or who are pregnant, complex multivitamin and mineral preparations promoted for use during pregnancy are unlikely to be needed and are an unnecessary expense.”

Women would be better off, they said, sticking just to vitamin D (10 mcg a day) and folic acid (400 mcg before pregnancy and until the end of the first trimester) and spending their money on a healthy diet.

This recommendation agrees with guidance from the National Institute for Health and Care Excellence (NICE). NICE bases its guidelines on the fact that studies show that folic acid reduces the likelihood of brain and spinal cord defects such as anencephaly and spina bifida in babies – and higher doses may be needed in women with greater risk of these conditions.

Similarly, there is evidence from the US that as many as 7 out of 10 pregnant women are deficient in Vitamin D. Research to support vitamin D supplements in strengthening the development of bones and teeth in babies is not as strong as for folic acid, but NICE, in line with current government policy, recommends it.

What you need to know

» In spite of the fact that we need healthy mothers to make healthy babies, pregnant women continue to get confusing and misleading advice on nutrition and supplements.

» A recent editorial in the medical press recommend that only folic acid and vitamin D supplements were needed to ensure a healthy pregnancy. This narrow view ignored the multiple reasons why some women might need a broader range of nutritional support.

» Targeted nutritional therapy, for instance through identifying deficiencies and risk factors, may be a more sensible way to approach supplementation during pregnancy.

What we know

Amazingly, given how much a healthy baby depends on a healthy mother, relatively little research exists on the nutritional requirements of healthy pregnant women. What little there is suggests that there is folly in mega-dosing or taking supplements “just-in-case”, but, again, even this deserves a closer look.

Studies have shown that mega-doses of vitamin A (retinol) may cause birth defects (ironically deficiency in this vitamin can cause the same thing).  The levels which are implicated are beyond what most women will ever take or get through their diets. Also not all forms of vitamin A are implicated. Beta carotene, a naturally occurring substance which converts into vitamin A in the body, appears to be safe. Nevertheless, it is probably wise not to exceed recommended doses for this nutrient during pregnancy.

Perhaps the biggest example of nutritional magic bullets, however, is the advice that all pregnant women should take folic acid.  There is strong evidence that, in high risk women, taking 400 ug/mcg of folic acid preconceptually and during the first two months of pregnancy may lower the risk of the baby developing spina bifida.

The problem is that there is no way of accurately addressing the question of who is at risk and who is not. In Britain for example rates of spina bifida are unusually high, suggesting an as yet unidentified environmental link rather than something inherently wrong with the baby making equipment of British women. Nevertheless, folic acid has been seized upon as a kind of cure-all. Some women take it as a form of ‘insurance’ long after they need to and long after it has been shown to be effective. With whole ranges of food being fortified with extra folic acid, a new question arises: can we get too much of a good thing? (for an alternative opinion on this see our article Folic acid in our flour – food sense or counsel of despair?).

Results of a recent study, released prior to publication, suggests the answer is yes. The study by researchers at Johns Hopkins School of Public Health found that if a new mother has a very high level of folate right after giving birth – more than four times what is considered adequate – the risk that her child will develop an autism spectrum disorder doubles. Very high vitamin B12 levels were also found to be potentially harmful, tripling the risk that her offspring will develop an autism spectrum disorder. If both levels are extremely high, the risk that a child develops the disorder increases 17.6 times.

On the other hand it is estimated that between 8-35% of women have a genetic glitch that prevents them from converting folic acid to its active form, 5-methyltetrahydrofolate (5-MTHF). For these women more bioactive forms of folic acid, for instance bound to either glucosamine or calcium, could help more than just randomly upping the dosage. But prenatal screening does little to identify these women and treat them with more appropriate forms of supplements.

On the plus side, there appears to be some truth in the idea that many women are deficient in certain nutrients which are relevant to their reproductive health.

One of these is zinc. Low levels of zinc have been found in women who have recurrent stillbirths and miscarriages, though it is not clear why this should be so. One theory is that women who have recurrent stillbirths may have extremely high levels of the toxic metals cadmium and lead.  Zinc is known to protect against both these elements and aid their excretion from the body and moderate supplementation may be a reasonable course of action. Yet no clear advice exists for zinc supplementation in pregnancy.

No recommendations exist for supplemental vitamin C or E and there is often confused information given regarding iron. Many women are deficient in selenium, but no advice exists for this vital nutrient either. Likewise women get no advice regarding essential fats, in spit of evidence to show that upping your intake of healthy fats during pregnancy could help protect against childhood allergies.

Nutritional therapy

Nutritional supplements are a mainstay of nutritional medicine. In a perfect world all our essential nutrients would come from food. But we all know that this is not a perfect world and that the idea of a perfect diet is a myth.

Also, as individuals, we are more than the sum total of what we eat. Outside factors such as the amount of stress we are under, whether we live in heavily polluted areas and what medications we are taking or have taken, will all affect how well we absorb and use the nutrients gained from our diets.

A nutritional therapist will always try to use supplements in appropriate ways and in appropriate amounts. This is in complete contrast to the practise of most antenatal clinics, where the tendency is to dole out single nutritional supplements in isolation and irrespective of the individual woman’s needs.

For instance, just giving a woman an iron tablet may not help boost her blood iron levels. Her problem may not be iron intake but iron absorption. Maybe what the woman really needs is a boost in her vitamin C intake either through supplements or by simply having a glass of citrus juice with her meals. In addition, excessive iron supplementation can deplete the body of another essential nutrient, zinc.

Another example would be calcium. Calcium absorption is aided by the presence of other minerals especially zinc and magnesium.

Sensible supplementation

Given the deficiencies in many of our diets, it is not unreasonable, and unlikely to be dangerous, for a woman to consider taking a good quality multi-vitamin and multi-mineral supplement during pregnancy to supplement – not replace – a good quality diet.

In this context “good quality” means a supplement which is free from unnecessary additives, and which contains natural complexes such as rice bran, sprouted barley juice, alfalfa all of which aid the absorption of vitamins into your system. Taking your vitamins with nutritious food, the original “natural complex”, can often aid their absorption and utilisation.

Multivitamins rarely contain enough of vitamins C and B-complex and during pregnancy these are particularly important.  In fact, if you are considering taking folic acid it is probably best to take it as part of a B-complex so that it may work more efficiently with other members of its “family”.

Vitamin C is also a “complex” and is absorbed best when the supplement includes bioflavonoids and other synergistic compounds such as rosehips.

Women who are vegetarians will need to pay special attention to their diets and make sure that levels of zinc, B-complex, calcium and magnesium are all adequate. For vegetarian women including dairy products in your diet will be helpful even if you don’t normally do this otherwise you may need to consider supplements.

Also women with dark skin, particularly if they are city dwellers, tend to be more prone to vitamin D deficiency during pregnancy. Ensuring you get 400iu of D and 500 to 1000mg of calcium daily may be appropriate in these circumstances.

Pregnancy vitamins - range

Click to enlarge.

Every woman’s needs are different. As a broad guide, the chart opposite lists the optimum levels for the essential nutrients during pregnancy.

Nutritional solutions for pregnancy

Looked at from a nutritional point of view, many of the common symptoms of pregnancy could be interpreted as a signal from your body to pay attention to how much, or how little, of the essential foods and nutrients it is receiving.  There is a wealth of research on this subject, most of it linking unpleasant prenatal symptoms to a deficiency of some sort.

The recommendations below are, however, general. If you feel you need extra help do consult a qualified nutritionist who will be able to advise you and monitor your progress.

If you have had unexplained previous problems in pregnancy, you may wish to consider having yourself tested either for vitamin and mineral deficiency or for high levels of toxic metals. The group Foresight can help with this.


There’s more to anaemia than simply low iron levels. A woman is said to be anaemic when her level of red blood cells falls below a certain point. Iron works with other nutrients in the body to increase red blood cell production and low levels of red blood cells can be the result of deficiency in B12, folic acid, manganese, copper and B6.

Vitamin C helps aid the absorption of iron in the body so consider supplements or take a glass of citrus juice with your meal. If you do resort to an iron tablet, make sure it is the more easily absorbed ferrous, not ferric, form. Look for preparations which include ferrous glucamate, ferrous flumerate and especially ferrous bisglycinate. You are unlikely need more than 40 -60 mg of elemental iron daily.


This condition, which causes thrush, is strongly linked to diet. Make sure you are getting enough vitamins A, B complex and C as well as the minerals zinc, iron and magnesium since deficiency of these may predispose you to attacks from fungi.  If you must take antibiotics make sure you also take pro-biotics in the form of acidophilous and bifidobacteria to help counter their harmful effect on the body’s “friendly” bacteria and minimise the chances of opportunistic fungi taking hold again.

Carpal tunnel syndrome

This uncomfortable condition, the result of extra accumulated water putting pressure on the nerves in the wrist (known as the Carpal tunnel), responds well to 100 mg daily supplements of B6.


A change of diet and plenty of water and exercise are still the best way to deal with constipation. However, increasing your intake of vitamin C may also help to alleviate the condition.  Aim to get at least one gram (1000 mg) daily from food and supplements.

Gestational diabetes

This is not the same as pre-existing diabetes and is likely to be caused by a temporary change in your metabolism during pregnancy.  In particular, vitamins of the B-complex family may be needed to help bring your body back into balance. Studies show that 100 mg of B6 daily can bring about a great improvement in this condition.

Haemorrhoids and varicose veins

Extra supplements of vitamin C, 1-2 grams per day, and vitamin E up to 800 iu daily can be effective. Taking essential fatty acids such as those found in fish oils or evening primrose oil will also maintain a healthy circulation. Adding natural fibre to your diet can help prevent constipation which can make haemorrhoids worse.


Inability to fall asleep or remain asleep is often related to stress. Because stress takes its toll on the body’s nutritional supplies try taking calcium, 100mg daily, together with magnesium, 200-500mg daily – the combination may produce a tranquillising effect. Stress can deplete levels of B-vitamins, so supplement with a B-complex which includes 50-100mg of the entire family.

If you have trouble maintaining sleep it may be because of night-time hypoglycaemia (a sudden drop in blood sugar in the night).  Make sure your supplement has adequate levels of nicotinamide (also known as niacinamide or B3) and take it before bed time. Don’t megadose as nicotinamide can place a strain on your liver in high doses. Unless otherwise directed, and under the consultation of a qualified nutritionist, take it as part of a B-complex.


During pregnancy your needs for B6, B12, folic acid, zinc and iron will all increase.  Adequate amounts of these nutrients are probably enough to ward off the nausea associated with pregnancy.  So if you are feeling very ill early in pregnancy, in addition to your minimum of 400mcg daily of folic acid, extra supplements of B6 in the region of 100mg daily may be needed. You may also require B12 in 50 ug/mcg doses daily. Symptoms should usually disappear within a week of two, in which case you should consider halving your dose. Zinc deficiency is also implicated in pregnancy nausea – aim for 20mg daily.


Pre-eclampsia is a potentially serious condition and you should always consult a medical professional for advice. From a nutritional standpoint, apart from careful attention to diet, and investigating the contribution of food allergies to her condition, a woman who has pre-eclampsia should consider increasing her intake of certain important nutrients. Chief among these are B6, calcium and magnesium. On their own, none of these nutrients have been consistently shown to help pre-eclampsia.

However supplementing with all three, especially if combined with an improved diet, may help prevent the condition from appearing, and may prevent a worsening of your condition (or even improve it) if it has already appeared.

Vitamin B6 should be taken in doses of 10-50mg daily; calcium 1000 mg daily and magnesium 400-600 mg daily. There is also research to suggest that supplemental vitamin E may improve pre-eclampsia. It is especially important to take pre-eclampsia seriously and take action at the first signs of its appearance.

Premature labour

If you have had a previous premature labour or are experiencing early contractions it may be a sign that you are deficient in certain essentials such as magnesium and calcium. Taking 1-2 g of calcium in the form of calcium gluconate or amino acid chelate per day combined with magnesium, 500-800mg daily, may help.  Also consider taking evening primrose oil 2-3 g daily. Always consult your doctor if you experience signs of premature labour.

Restless legs

This uncomfortable sensation in the legs, rather like an electric shock which makes you jittery and unable to sit or lie still, may be due to folate deficiency. In addition to any B-complex you may be taking, try increasing you intake of Vitamin E. There is evidence to show that doses of around 300 iu daily taken for around 3 months can be effective. Iron and magnesium deficiency may also come it play so make sure you are getting optimum levels of both. See also our article Q&A: What can I do about restless legs?


If your skin is giving way under the strain it may be a sign of zinc deficiency. Vitamins C and E are also necessary components of healthy skin. Applying vitamin E cream to the abdomen during the last few weeks of pregnancy may also help maintain your skin’s elasticity.