Are multivitamins for everyone?

Easily the most common supplement we as nutritionists encounter on a daily basis is a multivitamin. But is it really necessary?

From my experience, I often have clients taking a multivitamin, additional single vitamin/mineral supplement(s), sport supplements, and occasionally herbal supplements. How do we know what’s happening inside our bodies when mixing these supplements altogether? While sitting down with my clients, we will run through their list of active supplements and assess the reasoning behind taking each – sometimes I am met with a clear response where a client has done their research into why a mix of supplements is warranted (and sometimes it is), but other times and often times, I am met with clients uncertain as to why they are on so many supplements in the first place. More often than not, I will have clients who tell me they skip meals or skip the gym and want to be healthier by taking in their vitamins and minerals through a pill.

Can a daily multivitamin make up for frequently skipped meals, poor nutrition choices, poor sleep patterns, and inactivity? How much supplementation is too much? Can a supplement potentially do more harm to the body than good?

Recent research suggests a multivitamin may not induce all the benefits we hope it will provide. In fact, individuals with no nutritional deficiencies taking a multivitamin may be creating more harm than good in their bodies. According to an editorial review of 3 multivitamin trials and 24 trials of single/paired vitamins called “Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” published in the Annals of Internal Medicine (December 2013), current research suggests “no clear evidence of a beneficial effect of supplements on all-cause mortality, cardiovascular disease, or cancer”. Studies looking into the beneficial effects of multivitamins on outcomes of cognitive performance and prevention of cognitive decline are lacking or have resulted in disappointing outcomes. In fact, supplements such as containing B-carotene, vitamin E and high doses of vitamin A may be harmful in increasing mortality.

Multivitamins are like any other over-the-counter supplement – they vary widely in quality. Some may not contain the guaranteed amounts of ingredients listed. Others may exceed their listed values – excessive intakes of a single nutrient can be just as harmful as having inadequate amounts. Consumer Labs recently tested 42 different multivitamins independently. 16 of these failed to meet the nutrient levels declared on labels. Certain brands even exceeded tolerable upper limits or maximal amounts of a nutrient one can consume before experiencing harmful side effects. (e.g., excessive intakes of Niacin can result in skin flushing or tingling sensations; excessive calcium can result in the formation of kidney or bladder stones).

So you’re likely asking yourself…how do I know if I am getting meeting my vitamins and mineral requirements? A few things to consider:

  • Are there physical ailments involved where higher levels of vitamins/minerals are required (e.g. Crohn’s and colitis impacting nutrient absorption)?
  • Does my bloodwork indicate I need to focus on particular nutrients? (e.g. anemic conditions indicated by bloodwork)
  • How much of my nutrients are being met through diet (e.g. certain foods fortified with vitamins/minerals such as Vitamin D in milk or folic acid in flour)?
  • Am I on a special diet which requires me to focus on taking a single vitamin/mineral supplement (e.g. Vegans may require a B12 supplement)?
  • Am I taking any medications I am taking which requires me to have higher amounts of a particular nutrient (e.g. individuals on medications to manage stomach acidity may require B12 supplements)?


Lots to think about right? Working with a Registered Nutritionist can help you to hone in on what is truly required. Everyone is different; hence their nutrition needs to reflect individual differences. Simply taking a multivitamin will not solve a much bigger problem that’s brewing when one is regularly skipping meals, making poor food choices, compromising sleep, or neglecting regular activity.