- A multivitamin offers specific percentages of nutrients to help you reach daily needs.
- Maintaining a balanced diet is the ideal way to obtain nutrients, but a multivitamin can help, too.
- We asked three medical professionals what multivitamins should contain and how to know it’s safe.
- This article was medically reviewed by Véronique Taché, MD, an associate professor of obstetrics and gynecology at UC Davis Health.
Your body needs a certain amount of key nutrients every day for your organs, muscles, tissue, and overall systems to function properly. These are known as your Daily Value (DV) of nutrients. Multivitamins are a daily supplement that can help you achieve this recommended intake without taking a roster of pills, unless otherwise advised by your doctor.
I grew up reaching for my daily supplement every morning, yet I never gave the habit much thought. I soon realized that there is much ambiguity with multivitamins, from which one will “work” best to what makes one formula different from the next.
Because multivitamins aren’t regulated by the FDA, it’s important to ensure your multivitamin brand has been third-party tested and contains what it boasts on its label. As for what nutrients are ideal and who needs to look for specialized features, the advice is a lot less cut-and-dry.
I spoke with three medical experts — Uma Naidoo, MD, director of Nutritional & Lifestyle Psychiatry at Massachusetts General Hospital, Julie Garden-Robinson, PhD, RD, food and nutrition specialist and professor at North Dakota State University, and C. Michael White, PharmD, department head of the University of Connecticut’s pharmacy practice and dietary supplement researcher — to provide counsel on everything multivitamins. Here’s what you need to know when shopping for a daily multivitamin.
While multivitamins vary, there are specific topics to note as you’re assessing which tablet or gummy to add to your daily routine.
Should I take vitamins? And what vitamins should I be taking?
When it comes to what is considered an optimal nutrient, there isn’t a hard-and-fast rule. Garden-Robinson stands by the National Institute of Health, which advises speaking with your doctor who can have your levels tested based on your medical history to see if you’re low on nutrients like iron, B vitamins, or folate. This is the best way to ensure you know which nutrients are essential to add to your diet.
The Daily Value (DV) guidelines are set by the FDA to outline the optimal amount of each nutrient a person’s body needs in a day — and to prevent taking too much of a vitamin or mineral, which can become toxic. Obviously, the goal is to reach 100% DV for each vitamin and mineral. Going beyond 100% can have harmful side effects, including cramping, diarrhea, and nausea. This is especially true for fat-soluble vitamins A, D, E, and K (more on that below).
However, 100% DV is based on a 2,000 calorie diet. If you’re deficient in a certain area, over-supplementing above 100% DV may actually be what you need. This is why it’s important to get your levels checked and talk to your doctor about what your specific nutritional needs are.
Some artificial ingredients, like fillers and colorings, can contribute to disease development, like certain cancers, while others may increase cholesterol. Dr. Naidoo said some of the most common fillers to avoid in a supplement include starch, salt, hydrogenated oils, mercury, vegetable gum, and different types of sugars and artificial colorings. It’s best to avoid them if you can.
What does a multivitamin do for your body?
“In many cases, you can’t tell if a supplement is working because you may not have symptoms of a deficiency,” Garden-Robinson said. For example, you may not know you have osteoporosis, which results from low calcium or vitamin D intake, unless you have a bone scan.
She recommended keeping track of your moods in a journal or on your phone to document trends over time. If you were diagnosed with specific nutrient deficiencies through a blood test, she added, you may need follow-up tests to assess if your issue has been fixed.
As a PharmD, White said multivitamin intake is helpful if you have a specific deficiency or certain diseases. “If you have an issue with absorption because of something like Crohn’s disease, ulcerative colitis, or had part of your intestines removed (
), you’re going to need a multivitamin,” he said. “There’s not necessarily going to be one vitamin or mineral you’re deficient in. But other conditions, like macular degeneration, require a specific regimen.”
Garden-Robinson noted, however, that people with weaker bones, like those with fibromyalgia or older folks, may benefit from a calcium-vitamin D supplement or prescribed medication. Sometimes low levels of DHA and EPA may affect how quickly your brain fires, but taking a fish oil supplement may do the trick.
She added that if you do have low levels of a mineral or vitamin, you should follow the guidance of a medical care professional or pharmacist. You may need a prescription-level dose of a supplement.
For all of these specific concerns, Garden-Robinson advised seeking the advice of a medical care provider to ensure you are taking the most effective supplement, if any.
What’s the difference between fat-soluble and water-soluble?
“Water-soluble vitamins are those that are dissolved in water and, as a result, are easily absorbed into the tissues of the body for immediate use,” said Dr. Naidoo. “They’re not stored in the body, so they need to be replenished regularly in our diet.” Most vitamins, like B-complex and vitamin C, are water-soluble.
On the other hand, fat-soluble vitamins and minerals dissolve in fats, like the liver and fatty acids. Dr. Naidoo said these are slowly absorbed by fat globules within the body and then distributed throughout the bloodstream. That’s why fat-soluble vitamins like vitamins A, D, E, and K and are usually found in high-fat foods like salmon, sardines, or egg yolks. Ensuring you don’t go over 100% DV (unless instructed by your doctor) is important to avoid overaccumulation, which can become toxic.
As we mentioned, multivitamins aren’t regulated by the FDA, so efficacy is not guaranteed, nor is it consistent across brands and vitamin types. Here is an expert-backed cheat-sheet for key things to look for when shopping for your multivitamin.
How do I know if a brand is trustworthy?
“The best thing to do before taking any dietary supplement is looking to see if it has the USP label and NSF mark,” said White. “These are two independent laboratory-verifying organizations that will take the product and will test them to make sure they actually contain what the company selling it says it contains, and making sure it doesn’t have any contaminants, like mercury and lead.”
Equally important is running the vitamin you’re considering through Consumer Lab or Lab Door, both of which independently test formulas for accuracy, efficacy, and purity. Consumer Labs, as well as Consumer Reports, will also tell you about any brand recalls; even if your specific multivitamin isn’t recalled, frequent or recent recalls is a mark against a brand’s trustworthiness and quality control.
“Price does not indicate quality or nutrient content,” Garden-Robinson said. “Remember that dietary supplements are not regulated in the same way that food or drugs are regulated. The companies usually do not have to prove the supplement is safe or effective.”
That said, if you’re considering a pricier option that promises higher-quality ingredients, it should at least have a USP-Verified seal to confirm the supplement has met the strict standards for content and purity.
A vegan multivitamin should have two things: nutrients to supplement a
(namely vitamin B12, vitamin D, calcium, and omega-3s) and all plant-based ingredients, including plant-derived omega-3s and a vegan capsule, said Garden-Robinson. White adds that calcium is sometimes oyster-shell based, but an alternative to avoid shellfish is calcium carbonate.
What is the key difference between a men’s and a women’s multivitamin?
Even though they’re referred to as men’s and women’s multivitamins, the difference caters to common nutritional needs based on biological sex — that is, male versus female — not gender identity. Garden-Robinson said those labeled as “women’s” (catering to biological females) may have more iron and folate to meet recommendations for those who are pregnant or may become pregnant, especially to mitigate potential birth defects. An increased iron count is also due to blood loss during menstrual cycles. Also, because females are more at risk of osteoporosis, especially post-menopausal as estrogen levels decrease, some multivitamins marketed for women 40+ include a higher percentage of calcium.
Females are generally advised to intake more folate and iron as they are considering pregnancy or are already pregnant. Additionally, males may also be impacted by osteoporosis and may need more calcium once they reach 70. Aside from these key differences, the distinction between men’s and women’s multivitamins is simply marketing language communicated by the company.