Whether one is living with an overactive thyroid gland (hyperthyroidism) or an under-active one (hypothyroidism), the recommended diet is about the same. It is encouraged to eat a varied diet of nutritious foods in the correct amounts. The emphasis is on calcium and vitamin D-rich foods, such as:
- oily fish
- kale, collard greens, spinach
If you are intending on having a calcium-rich meal, please leave a gap of four hours between taking thyroxine and having the meal. This is because calcium can interfere with the absorption of thyroxine. Please note that lower-fat versions of dairy products remain the same in calcium levels.
Soya products should generally be avoided, as these can also interfere with the gland’s function. If somehow this is difficult, please leave as long a gap as possible between taking your medication and having soya.
A misleading food that some people believe is good for the thyroid is kelp. The British Thyroid Foundation recommends that kelp is avoided, as it contains high levels of iodine. Foods or supplements containing high levels of iodine can make an under-active gland function paradoxically worse; it can also trigger hyperthyroidism. Please be aware that certain sports formulae, such as milkshake powders, can contain high levels of iodine. If you are unsure of these, do consult with your doctor.
The thyroid gland does require iodine for normal function. Adults need 150 mcg of iodine per day.
We can generally obtain this from a varied, healthy (wholesome) diet that contains a balance of fruit, vegetables, nuts, seeds, fish and lean meat. Iodine-enriched salt is not recommended because, as explained above, it can worsen an under-active gland or trigger an overactive one.
In regards to iodine supplements, you should only take these if they are recommended by your health professional. If you are on iron tablets, it’s good practice to leave a two-hour gap between taking thyroxine and iron (iron can interfere with thyroxine absorption). Again, please discuss with your doctor or pharmacist. Do remember that some vitamin supplements contain iron.
We sometimes get asked if certain vegetables should be avoided with a thyroid condition. The most common ones that people wonder about are cabbage, cauliflower and kale. There isn’t really an issue with a normal consumption of these vegetables; one would really need to have excessive amounts before it could be a concern. These vegetables offer huge health benefits and should be encouraged as a part of a healthy diet.
Lastly, under the umbrella of general healthy eating, which also applies to the ‘thyroid diet’, comes the advice of low salt and saturated fat intake. And remember to eat real food!