The difference between the effect of nutrients and the effect of drugs

Nutrients primarily have a modulating effect. They inhibit or activate many different biochemical processes by acting on the underlying me- chanisms. They mainly have a beneficial effect on health over the long term. In the short term, their effect is much less pronounced than that of drugs.

Taking vitamins and minerals, which have more specific functions in the body than other bioactive substances, mainly has a pronounced effect on people with a deficiency in those vitamins or minerals and in people with genetic traits that increase their need for a particular vitamin or mineral. Taking supplementary vitamin D has much less effect on people who already have enough vitamin D than on people who are seriously deficient in it. As a result, the outcomes of studies are often contradictory.