When it comes to listing vitamins and minerals required for optimal health, it's not often people think about iodine. However this nutrient is vital to thyroid functioning, brain development and female hormone health.
The current RDA (Recommended Daily Allowance) (minimum intake) is currently low at 150 mcg per day (220 mcg for pregnant women and 290 mcg for breastfeeding women).
It seems that over the last 30-40 years we are getting a lot less iodine than we used to. Data for the UK and Ireland has shown that many parts of the country are not reaching an adequate daily intake of iodine. According to the Government's National Diet and Nutrition Survey, the average intake for women is 140mcg, with half getting less than 130mcg, and one in 40 as little as 48mcg or less. Men do a little better, but half still do not get their recommended daily intake.
A recent study published in the journal Lancet Diabetes and Endocrinology recommends that all pregnant women should be given iodine supplements as this could not only boost their babies' cognitive development and IQ but also save the NHS millions as iodine is vital for the developing brain.
Why are we deficient?
There are several reasons why many of us don’t get enough iodine. Soil worldwide is generally deficient in iodine, which in turn leads to only trace levels found in most foods. And, unlike other countries, iodine is not added to salt in the UK. There is also concern that toxins could be impacting iodine levels - for example fluoride and bromide (known as halides), have a similar structure to iodine, competitively inhibiting iodine absorption and binding in the body. So, the increasing levels of toxins in the environment and in food mean larger amounts of iodine are necessary to correct the deficiency.
How do I know if I am iodine deficient?
The following signs and symptoms may suggest the need for more iodine (N.B they can also indicate other health problems so it always advisable to discuss with your practitioner):
- cracks in the hands and heels
- chronic sinus infections,Upper respiratory infections and mucus
- Viral warts (verrucas)
- Ovarian dysfunction, low or high oestrogen
- Underactive thyroid gland
- Fibrocystic breasts
- Fatigue/brain fog
- Muscle aches and pains
- Dry skin and hair
- Persistently high cholesterol despite a healthy diet
Please note that too much iodine causes some of the same symptoms as iodine deficiency, including goitre so it's important not to over do it! Furthermore experts warn that concentrated supplements may not be safe, especially for pregnant women.
Where can I get iodine from in foods?
While it is difficult to get enough iodine from vegetables, nuts and cereals alone, it's easily possible to meet your iodine requirement as part of a balanced diet - iodine deficiency can be corrected by increasing your intake of fish, seafood and seaweed (or iodine fortified products). Note that when it comes to seaweed, only certain types have sufficient levels – top of the list are kelp, arame and hijiki.
If you feel that it is not possible to get enough iodine through your diet, then taking a supplement from a reputable company is a sensible solution.
Here are a list of foods found to contain high levels of iodine:
| Food Source || Iodine Content (approx) |
| Mackerel (100g) || 140 mcg |
| Cod (100g) || 100 mcg |
| Haddock (100g) || 100 mcg |
| Mussels (100g) || 140 mcg |
| Lobster (100g) || 100 mcg |
| Natural yoghurt (250g) || 87 mcg |
| Baked potato medium with peel || 60 mcg |
| Large egg || Up to 26mcg |
Dairy is one of the best sources of iodine however milk has varying levels over different seasons depending on how cattle are fed - full fat and lower fat milks have the same amount. Ice-cream, chocolate and milk based puddings such as a crème caramel all provide good levels in the form of a sweet treat but beware of their high sugar content!
Eggs are a great source and as they can be eaten in many different ways it's easy to introduce more of them into your diet, an added bonus is that the iodine levels found within eggs are largely unaffected by the cooking process.
Himalayan crystal salt naturally contains a range of minerals and trace elements including iodine. Don’t be fooled into thinking refined sea salt is a good source though as most is highly processed and devoid of iodine.
It is important to note that you need to be obtaining enough selenium in your diet also, which like iodine, is not always found in abundance in the average diet. Selenium is required for the metabolism of iodine and thyroid function. Brazil nuts are one of the richest dietary sources of selenium. Fish such as tuna and cod and turkey are also sources. Again, selenium can be taken in supplement form if you feel getting it from diet alone is going to be difficult.