Multivitamins – Are they safe, effective and worthy of your time and money?

pills and multivitamins on a black background

It’s a question I get asked a lot, “What supplement do you recommend or do you even recommend supplements?”

My answer tends to be pretty complicated as I am in the middle and can see the benefits as well as the reasons why some don’t want to or don’t feel the need to take multivitamins. Let me share some evidence, things to consider, and then you can decide for yourself.

Back to Basics
Multivitamins, just as their name implies, contain numerous different vitamins and minerals. There is no set number that is required to be contained within various brands making it hard to compare which would be the best. Not to mention, multivitamins fall into the supplement category and are not regulated – unlike our food and beverages- by the FDA or USDA.

People tend to take multivitamins for a variety of reasons from preventing conditions like cardiovascular disease, eye conditions like cataracts and age-related macular degeneration, as well as various cancers, Alzheimer’s, and to overall improve wellbeing, focus, cognition and longevity.
Think of multivitamins as a back up to your regular diet. Of course, we want to get our nutrients from our food rather than from a synthetic supplement, but when we consider the fact that we aren’t perfect, neither is our eating and neither do we need to expect ourselves to be, multivitamins can help ensure and fill in the potential gaps of what we need.

Are they effective?
Despite our reasons for taking supplements, there is limited evidence for the actual effectiveness of taking multivitamins. The one exception is for age-related macular degeneration; most clinical research supports supplementing with a multivitamin with 500 mg vitamin C, 400 IU of vitamin E and 15 mg of beta-carotene with or without zinc. This seems to reduce loss of visual acuity and risk of progression for those at risk of age-related macular degeneration.

Are they safe?
In addition to efficacy, we always consider safety. There are upper limits set for how much nutrients we need each day, and exceeding these daily limits can put us at risk for adverse effects (so in this instance, there’s truth to the old adage that too much of a good thing can still be bad for you). Fortunately, multivitamins do seem to be safe when taken and when in consideration of our dietary reference intake (DRI) – think of them as daily recommendations. You can search your DRIs (consisting of both recommended dietary allowances as well as tolerable upper limits) online and view an entire chart based on your age and gender to see how much of various nutrients you need per day.

Remember there are different types of vitamins, and we can classify them into fat soluble (or fat stored) and water soluble. If we take excess of water soluble, we are less at risk for adverse reactions as they will be excreted in urine, but we are quite literally flushing our money down the drain. Fat soluble ones, on the other hand, have a bigger potential of being stored in our fat cells, making us more susceptible to potential toxicity.

What specifically to look for?
Consider your usual daily diet. Do you intend to get in two servings of fruits and low-fat dairy each day, along with plenty of veggies and lean proteins and whole grains or fiber on a regular basis, but fall short on occasion?

If so, then try to find brands with mostly 100% daily values (DV) down the side of the supplement facts panel. You won’t find this for calcium and iron, see later for why.

If you don’t eat enough calcium-rich foods, as an example, and your supplement is not making up the difference, then you would need to revamp your food intake to accommodate or possibly add a separate calcium supplement. Other scenarios where you may need to look at specific nutrients would be if recent lab testing comes back and shows you have low iron stores or you are vitamin D deficient. Your medical provider may recommend amounts that are higher than the percent daily value listed. Additionally, vegans need a vitamin B12 supplement, as B12 is only found in animal products, and since vegans do not consume any animal products, they must get it from a supplement.

Any brands in particular?
Adults: Kirkland Signature (Costco) Daily Multi providing 100% of recommended daily intake of many vitamins and minerals but not exceeding any upper tolerable limits
Women: Up and Up (Target) Women’s Daily Multivitamin
Men: Berkley & Jensen’s (BJ’s) Men’s Daily Multivitamin & Minerals
Children: Flinstone’s Gummies Complete

Myth buster #1: You have to buy gender-specific supplements.
False: If you look up the DRI charts, you’ll see that nutrients vary widely by age, but for males and females, their needs are relatively the same with some minor exceptions, which could be made up for through one’s diet. Children need much less of each nutrient simply because of their smaller body sizes. Whereas, pregnant and nursing women need more to account for their own needs plus what they share and provide to their baby.

Other Special Considerations
Make sure to store them in a cool, dry place. Next to your hot oven or steamy shower isn’t the most ideal spot, especially in hot and humid Louisiana. Oddly enough, this is where most “medicine cabinets” are located.

Iron and calcium compete for absorption in the body so whether it’s with food or with supplements you want to consider taking them separately. Consider milk or yogurt (popular calcium sources) with snacks so meal times can be reserved for iron absorption (like lean red meat).

Myth buster #2: Plants are rich in iron.
While plants are a rich source of iron, our bodies cannot utilize or absorb this form of (non-heme) iron as efficiently as heme (or hemoglobin) iron. A way to help remedy this is to pair plant-based iron sources like dark leafy greens (spinach, kale, greens, etc.) with vitamin C food sources like citrus, berries or peppers.

Spinach and strawberry salad
Sautéed spinach with squeeze of lemon juice
Kale salad with orange segments or peppers

If choosing a gummy vitamin for kids, it’s best to take them before bedtime, remember to brush their teeth afterwards – before going to bed.


Rebecca Miller, MPH, RDN, LDN is a registered dietitian nutritionist. She writes a blog called Twisted Nutrition ( and can be reached for questions at

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