Vitamins and minerals in the prevention of disease: The evidence

Abstract

A huge number of experimental results and the observations of epidemiological studies have opened wide possibilities of the use of vitamins and minerals in primary and secondary prevention of disease. This kind of health care concept, backed by media and marketing campaign, has been thoroughly established in general population. The randomized controlled double-blind trials possess the highest value in hierarchy of evidence for claims on the efficacy and safety of a treatment. Such investigations of the use of vitamins and minerals in disease prevention (cancer, cardiovascular diseases, respiratory infections, fractures, dementia, neonatal morbidity) have mostly produced, up to date, the null results. The obtaining of the affirmative results of preventive effects of vitamins and minerals, in the settings of the lack of clear deficiency, appears to be an exception needed to be revealed, but not a rule ready to be confirmed. Furthermore, the results of meta-analyses which show that the use of certain antioxidant vitamins (vitamin A, beta-carotene and vitamin E) may be associated with an increase in mortality in comparison with the control group ask for an additional attention.

Veliki broj eksperimentalnih nalaza i rezultata epidemioloških istraživanja ukazuje na široke mogućnosti primene vitamina i minerala u primarnoj i sekundarnoj prevenciji bolesti. Ovaj koncept brige o zdravlju, podržavan medijski i marketinški, postao je široko prihvaćen u opštoj populaciji. Randomizovana kontrolisana dvostruko slepa ispitivanja imaju najveću vrednost u hijerarhiji dokaza za tvrdnje o efikasnosti i bezbednosti primene nekog tretmana. Ovakva ispitivanja primene minerala i vitamina u prevenciji bolesti (kancer, kardiovaskularne bolesti, respiratorne infekcije, frakture, demencija, neonatalni morbiditet) dala su, za sada, najčešće, neutralne rezultate. Dobijanje afirmativnih rezultata preventivnih efekata unošenja vitamina i minerala, u uslovima kada ne postoji jasna deficijencija, predstavlja izuzetak koji treba otkriti, a ne pravilo koje treba potvrditi. Posebnu pažnju pobuđuju rezultati meta-analiza koji pokazuju da bi primena određenih antioksidativnih vitamina (vitamin A, beta-karoten, vitamin E) mogla biti povezana sa povećanjem mortaliteta u odnosu na kontrolnu grupu.