Should whole-food plant-based eaters worry about iodine?  

It is estimated that one in seven globally are iodine deficient and plant-based eaters may be particularly vulnerable.

Why? Three major sources of iodine in the standard diets are seafood, dairy and iodised salt. It occurs naturally in seafood. In dairy, iodine is used in cleaning the milking equipment and since the 1920s some countries have been fortifying salt with iodine.

So, there is an iodine dilemma here. Do we supplement? Do we need to? Despite the 1 billion people consuming too little iodine, hypothyroidism and goitre (two of the main symptoms of iodine deficiency) are not as common.  It may be that some of us are eating pulses and vegetables grown in iodine-rich soil and fulfilling our needs that way.

However having adequate iodine during pregnancy is vital for both mother and baby.  A deficiency can increase the risk of miscarriage, preterm birth and low birth weight.  It can also affect brain development.

In the UK, the vast majority of salt consumed is not iodised. It is, however, available. Plant-based eaters may choose to eat sea vegetables to fulfil their needs if they wish to avoid salt and supplements.

And it starts to get complicated.

The daily recommended intake is 150 µg. The upper tolerable level before it starts causing problems is 1100 µg a day. The amount of iodine in seaweed varies enormously so it is worth getting out your calculator and checking that you’re not over-doing it on a regular basis.

But what about those of us who actually don’t (yet) love sea vegetables? Dr Greger of NutritionFacts.Org recommends using dulse flakes as a sprinkle or eating two sheets of nori a day. He cautions against hijiki and kelp.  It is also essential to proceed with caution and take advice if you have any thyroid condition.

A whole range of sea vegetables grow around the British Isles so we set out to explore. First up is a gutweed and sea lettuce mix. It has a fairly mild aroma and just requires soaking in cold water for 20 minutes before adding to food.  We added it to a stir fry which worked out fine.  It did impart a subtle seaside flavour, but nothing unpleasant.  Only a small amount is needed to achieve the recommended iodine intake.  On the back of some packs of seaweed, the producers provide an indication of iodine content, so you can gauge how much to eat.

We’ve also tried out sea spaghetti, which, when added to soup-based noodles makes for an interesting addition which combines well with dried mushrooms, pak choi and spring onions.  

We have such a plethora of sea vegetables available - some are safer to consume than others, but it’s worth exploring and as we all know, sometimes we have to try a new food several times before we learn to love it.

Happy exploring!