Should you take a multivitamin to improve overall health, make up for an unhealthy diet, and/or protect against disease risks? The multivitamin industry earns billions of dollars every year – making multivitamins the most widely consumed supplement worldwide. But do they really work? Are they worth the investment for your health?
How do Multivitamins Work?
Multivitamins are supplements that contain different combinations of vitamins, minerals, and/or other healthy/supposedly healthy ingredients, such as amino acids, enzymes, and herbs. The combination varies per product and brand, and there are no established standards that define what should be included in a multivitamin.
Some multivitamins are promoted as dietary supplements that will boost intake of certain substances that are vital to health, especially if these substances are lacking in one’s diet. Others claim to help reduce the risk for certain diseases. However, they are not marketed nor are they supposed to replace the essential vitamins and minerals that should be derived from a well-balanced diet.
Likewise, multivitamins cannot claim to prevent, diagnose, and/or treat diseases; such claims cannot be proven as true because these supplements do not undergo FDA approval.
As long as dietary supplements only include ingredients that have already been reviewed by the FDA, they do not need to be approved for safety and effectiveness by the agency. But if a new ingredient is included, the manufacturer must notify the FDA so it can be reviewed. The FDA has the authority, however, to take a product off the market if it has been found to cause serious health problems or if it has been reported to have false and misleading claims.
Multivitamins are available as capsules, chewables, liquids, powders, and tablets. Depending on the dosage per intake, they are usually taken once or twice daily. They can be purchased over-the-counter at pharmacies, as well as in supermarkets, local grocery stores, health stores, and online.
Multivitamins and Health Benefits
Scientific evidence that taking multivitamins can be beneficial to health is mixed and inconclusive. But a lot of people still take these supplements as part of their “healthy” efforts. Below is a list of these supposed health benefits and what studies have revealed about them so far.
- Preventing heart disease. Some studies have found a correlation between intake of multivitamins and reduced risk of heart attacks and death; but other studies have shown zero correlation.
- Reducing cancer risk. Some studies have linked multivitamins to a reduced cancer risk, particularly among men; others have shown no such benefit; and some suggest that the supplements may increase cancer risk.
- Improving mood and brain function. Nutrient deficiencies have been linked to poor mood, and some research has found a correlation between multivitamins and improved mood or reduced symptoms of depression. Studies have also shown that multivitamins may improve the memory function of aging adults.
- Improving eye health. One study has found that the progression of age-related macular degeneration may be slowed down, but not prevented, by taking antioxidant vitamins and mineral supplements. Multivitamins may also reduce the risk of developing cataracts.
Who Should Take Multivitamins?
Healthy individuals do not need to supplement their diet with multivitamins; some individuals may actually be harmed by taking certain supplements. But there are also populations that can benefit from them.
- Pregnant and breastfeeding women are often prescribed with iron and folic acid supplements, depending on their overall condition and as determined by their doctor.
- Older adults may need to take supplements for vitamin B12, as absorption of this vitamin decreases with age, as well as for calcium and vitamin D.
- Vegans and vegetarians are normally lacking in certain essential nutrients that can only be derived from animal food sources. These include vitamin B12, calcium, vitamin D, iron, zinc, and omega-3 fatty acids.
- Other groups that should consult a health professional regarding supplementing with multivitamins include people who suffer from poor appetite, are on a low-calorie diet, have undergone weight-loss surgery, or have a condition linked to a specific nutrient deficiency.
Precautions When Taking Multivitamins
- Always follow the recommended dosage when taking multivitamins.
- Vitamins A and D are fat-soluble vitamins, which means that the body cannot easily get rid of any excess amounts taken. Overconsumption of these vitamins over a prolonged period can lead to toxicity.
- Pregnant women should take vitamin A supplements with extreme caution as excessive intake may lead to birth defects.
- Smokers should avoid multivitamins that contain a lot of vitamin A as these can increase lung cancer risk.
High doses of iron in people who don’t need iron supplements can be harmful. - If your diet already contains a lot of nutrient-dense foods, taking multivitamins can result in exceeding the recommended daily intake of certain nutrients.
- Always buy from a trusted manufacturer/brand. Many small-scale manufacturers of multivitamins, and even big ones, formulate products that contain higher or lower levels of nutrients than what is stated on their labels.
- Some ingredients in multivitamins are derived from real foods, while others are synthetic/created in a lab.
Should You Take Multivitamins? – Bottom Line
The safest and most effective way to promote optimal health is through a naturally nutritious diet. Ideally, you should obtain all the essential nutrients your body needs from the food you eat. Most healthy individuals do not need to supplement their diet with multivitamins.
There is mixed evidence regarding the health benefits of multivitamins. There are some instances when certain supplements and/or taking too high a dose can cause serious harm. It’s important to follow the recommended dosage for any multivitamin. And always consult a doctor regarding supplementing with multivitamins, especially if you have a certain health condition, are following a highly restricted diet, are pregnant, are breastfeeding, or an elderly.
Lastly, multivitamins should not be taken to make up for a poor diet and the poor health that results from it. Adopting healthier eating habits and eating more whole foods are always the best solution.
