'Multivitamins a waste of money' report and considerations to take
Earlier this week, a group of American researchers published an editorial and three articles in the Annals of Internal Medicine journal with an uncharacteristically blunt statement:
"Stop wasting money on vitamin and mineral supplements."
The three studies each addressed a different role of vitamin and mineral supplements. The authors came to this conclusion
- There is no clear evidence of beneficial effects of supplements on all-cause mortality, cardiovascular disease, or cancer.
- Multivitamins do no prevent cognitive decline with well-nourished elderly people.
- No difference in recurrent cardiovascular events with multivitamins compared with placebo.
Leslie Beck, a Toronto-based registered dietitian, says this report does not provide any new information.
"We’ve always known that taking a multivitamin doesn’t prevent cancer, lower risk of heart disease or stroke," said Beck. "That's not why dietitians recommended take multivitamins. The purpose taking a multivitamin or a mineral supplement is to bridge nutrient gaps in your diet."
This nulls the first and third sub-studies, which looked for results of decreasing risks of cardiovascular and coronary heart diseases, cancer, and even death.
Excludes population groups who are more in need of vitamins than well-nourished people
While the studies have fairly large study groups, these studies are flawed in the groups it is not observing. By only studying placebo and control group who takes multivitamins, the study is weakened by not looking at people who took nothing at all. There is observational bias in all three studies by leaving out groups of people who are especially in need of vitamins to fulfill their nutritional requirement.
Beck notes that not every eats a perfectly well-balanced diet, some people eat low-calories, or have dietary restrictions.
"It's challenging for women who are menstruating to meet iron alone," said Beck. "Any woman of childbearing age should be getting 0.4 mg of folic acid, in the chance they become pregnant. Adults over 50 are recommended to get vitamin B12 from a supplement or fortified foods because as we get older, it gets harder to absorb it in our diet."
The study notes that over-supplementing on certain vitamins, such as vitamin A and E cause more harm than help, which Beck agreed with. It also excluded vitamin D supplements from being "ineffective" and said it needed more research.
"If the sole reasons you’re taking a multivitamin is because you think you won’t get cancer, then, yes, you're wasting your money."