Vitamins that should not be taken together:
It is not recommended to take iron with calcium supplements as it interferes with the iron.
Mineral supplements with each other
Avoid taking magnesium and calcium together.
It is not recommended to take copper and zinc supplements together as copper deficiency can result from high levels of zinc.
vitamin C and vitamin B12 as vitamin C could break down vitamin B12
in your digestive tract and reduce absorption.
vitamins D, E and K as vitamins D, E, and K may reduce absorption when taken together