What to Eat When You're Pregnant and Vegetarian : Other essential vitamins and minerals (part 5) - Zinc, Iodine, Selenium

Iodine

What it’s for: Iodine is important for the development of the nervous system, particularly during the first three months of pregnancy. Babies of iodine-deficient women can have poor mental development. Iodine is also needed for the production of thyroid hormones. Deficiency is extremely rare in European countries, but women with marginal intakes can start to show signs of deficiency during pregnancy. The most obvious sign of deficiency is a goitre, which is a large swelling on the neck.

Amount needed: 140µg per day.

Where it’s found: The main sources of iodine for lacto-ovo-vegetarians are milk and milk products. Research has shown that organic milk has around 40% of the level of iodine contained in conventional milk, reflecting the lower iodine intake of the cows. Therefore if you have organic milk, it’s important to ensure you get enough iodine from other sources. Using salt with iodine added (iodised salt) is one way of increasing your intake, but obviously lots of salt isn’t good for heart health.

Seaweed is an excellent source of iodine and is becoming increasingly easy to find. Dried seaweed is available in healthfood shops and many supermarkets, or if you know what you’re doing, you can get it from the sea. You need to be careful about what type of seaweed you eat and how much you have, as some varieties contain incredibly high levels of iodine, so it is easy to have too much (see table). Very high intakes can interfere with thyroid function and it is not advisable to have more than about 300µg of iodine per day. The Vegan Society suggests that kombu is a good source of iodine, as it seems to have a fairly consistent iodine content. If you have a shaker in the kitchen containing 15g, this is sufficient for one person for a year (about 180µg per day). It may be easier to monitor if you have a smaller amount – say 3g for three months’ supply (around 145µg per day).

High intakes: Cases of vegetarians having excessively high intakes of iodine are occasionally reported. These are usually associated with high intakes of kelp but there is also a risk if several different sources of iodine are taken, for example iodised salt, seaweed and supplements. If you are getting iodine from several sources, it’s important to monitor your intake.

Selenium

What it’s for: Selenium is an antioxidant and therefore protects against cell damage. It also plays an important role in the immune system, thyroid hormone metabolism and reproduction. Research suggests that having a good intake of selenium during pregnancy may reduce the risk of your baby developing eczema and wheezing, which can be an early sign of asthma.

Amount needed: Women are advised to consume 60µg per day in pregnancy and 75µg per day while breastfeeding. Selenium intakes in the UK have fallen since the 1970s when we started eating more wheat from Europe and less from North America, where the soil is more selenium-rich. Average intakes are now below recommended levels for meat-eaters and vegetarians alike. Studies comparing selenium intakes and blood levels of selenium in lacto-ovo-vegetarians, vegans and meat-eaters have had mixed results, with some concluding that vegetarians’ intakes are especially low but not others.

Where it’s found: Selenium is not found in a wide range of foods. Brazil nuts are an excellent source and have been found to contain between 85 and 690µg per 100g, which is an incredibly wide range but reflects the levels found in different soils. If you have chocolate, or carob, coated brazils then you can have a treat but know you’re getting something healthy too.