Writing in the BMJ Open​, the US-based team finds multivitamin/mineral supplement (MVM) users reporting 30% better health than non-users with no difference between the two groups when testing psychological, physical or functional health outcomes.

“The effect of positive expectations in [those who take multivitamin/mineral supplements] is made even stronger when one considers that the majority of [them] are sold to the so-called ‘worried-well’,”​ the team from Harvard Medical School writes.

“The multibillion-dollar nature of the nutritional supplement industry means that understanding the determinants of widespread [multivitamin/mineral] use has significant medical and financial consequences.”

Vitamin D in spotlight

Interest in multivitamins or mineral supplements has surged this year owing to the pandemic, in which consumers have turned to vitamins, minerals and botanical ingredients to support immune function.

This is no where more clearly shown than with vitamin D, where a spate of news linking its efficacy against the coronavirus is giving credence to its effectiveness.

Its cost effectiveness and ease of distribution is also a factor as the UK government looks to follow Scotland’s example by offering free vitamin D supplies​​ to those shielding during lockdown.

While multivitamin/mineral supplementation is justified for individuals at high risk because of disease-related deficiency, their consumption has not produced robust evidence for the health benefits expected by the general adult population.