The exact intake recommendations can be found on the respective product packaging and on the label. In principle, fat-soluble vitamins (for example, vitamins A, D, K) should ideally be taken with a meal and not on an empty stomach. Zinc should preferably be taken in the evening, ideally on an empty stomach. If the recommendation is to take the preparation twice a day, you should stick to this, because the body cannot fully absorb too much of the active ingredient at once. Furthermore, you should avoid foods that inhibit absorption, such as coffee or black tea. It is known that phosphates in sausage or soft drinks inhibit the absorption of calcium and magnesium. Sugar, salt and protein-rich foods favour the excretion of calcium. Sugar also blocks the absorption of chromium.