Getting enough iodine is crucial for healthy thyroid function, which controls your metabolism.
An iodine deficiency during pregnancy and early infancy can result in irreversible mental retardation (41).
In adults, insufficient iodine intake can lead to hypothyroidism.
This can cause symptoms such as low energy levels, dry skin, tingling in hands and feet, forgetfulness, depression and weight gain (41).
Vegans are considered at risk of iodine deficiency, and studies report that vegans have up to 50% lower blood iodine levels than vegetarians (42, 43).
The RDA for adults is 150 mcg of iodine per day. Pregnant women should aim for 220 mcg per day, and those breastfeeding are recommended to further increase their daily intake to 290 mcg per day (44).
Iodine levels in plant foods depend on the iodine content of the soil. For instance, food grown close to the ocean tends to be higher in iodine.
The only foods considered to have consistently high iodine levels include iodized salt, seafood, seaweed and dairy products, which pick up iodine from solutions used to clean cows and farm equipment.
Half a teaspoon (2.5 ml) of iodized salt is sufficient to meet your daily needs.
Vegans who do not want to consume iodized salt or fail to eat seaweed several times per week should consider taking an iodine supplement.
BOTTOM LINE:Iodine plays an important role in your thyroid function and metabolism. Vegans not getting enough iodine from seaweed or iodized salt should consider taking an iodine supplement.