Most parents’ idea of giving their child the best start naturally centres on post-natal issues like breastfeeding and a safe nurturing environment, but important though these are, other factors can influence their offspring’s long-term future long before they are born. Indeed, sometimes even before they are conceived.

We have known for many years that parental lifestyle, particularly smoking and alcohol, impact on the development of a growing baby and leave scars that can stay with them for the rest of their life. But the role of essential nutrients – or lack of them – hasn’t always been so well understood. And, while any sensible would-be parent will do their utmost to improve their diet and lifestyle, most don’t take adequate steps to take in enough micronutrients to fully protect their baby.

New research published in the latest edition of The Lancet has highlighted a worrying link between iodine deficiency and low IQ in children. The team behind the study found a direct correlation between mild to moderate iodine deficiency during pregnancy and lower than average IQ scores in subsequent offspring. An alarming finding given that a study published five years earlier in the same journal suggested that more than half of UK school girls had some degree of iodine deficiency.

And then there is folic acid, high doses of which (400mcg a day) reduce the risk of spina bifida and related conditions. Since the early nineties women have been advised to take a daily supplement from before conception until the twelfth week of pregnancy, yet surveys suggest that most don’t.

An on the subject of supplements, why do so few pregnant women take extra vitamin D (surveys in my practice suggest no more than 20%) despite long standing advice that they should all do so? Although typically associated with rickets, nearly every cell in the body has a receptor for vitamin D and it is becoming increasingly clear that there is much more to its role than maintaining healthy bones. Researchers are currently looking at its role in predisposition to diseases as diverse as cancer of the colon, dementia, multiple sclerosis and diabetes (children born to mothers with low levels of D are more likely to develop diabetes and supplements appear to protect them).

A team from the University of Sheffield has shown that as many as three-quarters of women giving birth in Spring have sub-optimal vitamin D levels – Spring being the worst time of year for deficiency as the vitamin is manufactured in the skin when it is exposed to sunlight and none of us get enough during the dreary winter months.

So what can women do about these three? There are no hard and fast guidelines on iodine intake during pregnancy other than pregnant women should try and achieve 250mcg a day (see above) through their diet, and be wary of natural seaweed or kelp-based supplements as the iodine content can vary tremendously and you may end up taking too much. Advice regarding folic acid and vitamin D is much clearer – take a supplement whatever your natural intake through diet or exposure to sunlight.

I don’t normally advocate multivitamin and mineral supplements but pregnancy (and the months leading up to it) seems the ideal time to take one that has been specifically formulated for the job (general supplements often contain too high a level of vitamin A). And there are a number of daily products on the market that contain the right amount of folic acid (400mcg), vitamin D (10mcg) and iodine (140 -150mcg), as well as a few other vitamins and minerals you probably don’t need.

But please bear in mind that supplements are not substitutes for a healthy balanced diet. In general it is always better to try and meet your daily requirements through eating the right foods, but for iodine that can be difficult if you are a vegetarian or don’t eat fish, and often impossible for vitamin D and folate due to the high intakes required.


For more advice on diet and supplementation during pregnancy visit


• Iodine is essential for the manufacture of thyroid hormones which, in turn, influence the development of a baby’s brain

• Iodine deficiency is now common among pregnant women

• The recommended daily intake is 250mcg and good natural sources include cow’s milk (50 – 80mcg per 200ml), yoghurt (up to 100mcg per 150g), and white fish (115mcg per 100g)

• Visit for more detailed information