Low potassium diets may be recommended by healthcare professionals for several reasons but usually it’s in relation to kidney disease.
Medication can contain potassium, although this is usually in small amounts. The Pfizer vaccine contains a very small amount of potassium, less than 1mmol or 39mg per dose, which is classified essentially ‘potassium-free’. The other vaccines used in the UK (AstraZeneca and Moderna) do not list potassium as an ingredient.
Therefore it is unlikely that any of the vaccines available in the UK would need to be avoided if on a low potassium diet.
For more information on the vaccines available in the UK please visit the NHS website.