Potassium Iodide Anti-Radiation Tablets (130mg, 60 count)

This is one of those items you hope never to use, which is exactly why it belongs on a shelf instead of on a shopping list after the fact. In a nuclear emergency, potassium iodide helps protect the thyroid gland from absorbing radioactive iodine.

Two things matter here. It protects the thyroid only, not the rest of the body. And it should be taken only when public health officials tell you to, following the dosing on the package. Keep it with your family's medical supplies and check the expiration date when you rotate your storage.