Medically Reviewed by
Diana Morgan, MS, CISSN
5 min read
Almost everyone has some experience with vitamins, even if the last ones you took were shaped like a cartoon family. However, with thousands of products on the market, the process of choosing the right vitamins and supplements can be overwhelming. The process is made even more complicated by contradicting information and misleading advertising. You know there is a way to improve your long-term health, but how can you make sure you are taking the right vitamins and supplements?
The key is to know what essential vitamins and nutrients to look out for, to carefully assess your diet, and to consider how your lifestyle and long-term health goals come into play. Remember that vitamins and supplements are not meant to replace a healthy diet. Beyond nutrients, fresh fruits and vegetables provide antioxidants, phytochemicals, and fiber, all of which are important.
At the most basic level, vitamins are essential organic substances your body’s cells require to function, grow, develop and heal properly. (In this context, “organic” means they contain the element carbon.) There are 13 “essential vitamins”: vitamins A, C, D, E, K, and the B vitamins, B6, B12, biotin, folate, niacin, pantothenic acid, riboflavin, and thiamine. A major deficiency in any one of these vitamins could lead to serious health problems.
In addition to the 13 essential vitamins your body needs, there are 16 essential minerals, all of which you might recognize from the periodic table. Unlike vitamins, minerals are “inorganic,” meaning they do not contain a carbon atom.
Macrominerals are the minerals that your body needs in relatively large amounts; trace minerals are those that your body needs in small amounts. The essential macrominerals are calcium, chloride, magnesium, phosphorus, potassium, sodium, and sulfur. The trace minerals your body requires are iron, zinc, iodine, chromium, copper, fluoride, molybdenum, manganese, and selenium.
Another nutrient to note is choline, which is widely understood to play a critical role in nerve and brain function. Meat, eggs and poultry are all excellent sources of choline. Strict vegetarians may want to consider taking a choline supplement.
Each of the essential vitamins and minerals plays a complex set of roles in the body. Magnesium, for example, is a vital element in over 300 biochemical reactions, ranging from protein synthesis to nerve function. It is not hard to imagine the broad potential for health symptoms to arise from a deficiency in this one mineral.
In addition to vitamins and minerals, there are other nutrients that are backed by established research, including omega-3 fatty acids. Additionally, antioxidants such as CoQ-10, are gaining recognition for their essential role in the healthy function and immunity of the body’s cells. These examples represent opportunities to improve wellness beyond the basics of vitamin and mineral intake.
The US Food and Drug Administration sets a Recommended Daily Intake (RDI) for the essential nutrients to help people manage their nutrition.
The RDI is simply how much of each nutrient is needed each day for healthy adults. It is typically measured and listed using one of three different units: milligrams (mg), micrograms (mcg), or international units (IU). The nutrition labels on foods will list the nutrients they contain, as well as the percentage of your RDI for each particular nutrient.
This information is helpful to ensure that you are not consuming too much or too little of any nutrient in a given day.
One way to figure out what vitamins and supplements to take is to look carefully at the nutritional value of all the foods in your diet and see how close you come to the RDI recommended by the FDA for each essential vitamin and mineral.
If you have a diet that’s particularly low or high in certain foods, you could be getting too much or too little of certain nutrients. For example, vitamin B12 is commonly found in non-vegetarian food sources, so if you’re a vegetarian, you may be getting less than the RDI of that vitamin.
If the RDI represents the low end of the amount you need for a particular nutrient, then the UL (“Upper Limit”) represents the high end. It is only advisable to begin taking a supplement if you are confident that you are not presently meeting the RDI and unlikely to exceed the UL.
In some cases, having too much of an essential vitamin or mineral can be as dangerous as having too little. For example, too much potassium can cause diarrhea, vomiting and an irregular heartbeat. This condition can arise from the overuse of potassium supplements, so be careful when considering any dietary supplements and always be mindful of the upper limits for vitamins and minerals.
With some healthy nutrients, the FDA doesn’t issue clear directions on daily intake, but helpful guidance is available. For example, the USDA recommends eating fish or seafood twice a week, which may be difficult for some people.
However, regular consumption of omega-3 fish oil capsules can provide much of the same benefit. There is also a great deal of emerging science supporting the potential benefits of herbal and antioxidant supplements, which have shown results in certain cases.
The RDI is a useful benchmark for the bare minimum of the essential nutrients an average person needs. However, this one-size-fits-all approach can still leave potential gaps in your nutrient intake. Depending on your health goals and lifestyle, the RDI may be lower than your actual needs.
Factors like age, gender, fitness level, and geographic location can mean that a person needs more or less of a given nutrient. For example, women entering their 50s might be more in need of bone-strengthening vitamins to help protect against osteoporosis. Women thinking about getting pregnant, on the other hand, need more of a different set of vitamins, like folate and iron.
You also may want to get more or less of certain vitamins depending on your specific short-term and long-term health goals. If you have trouble sleeping, or if you’re concerned about long-term heart health because of your family history, taking supplements could help.
Even the most health-savvy individuals could benefit from a professional opinion or alternative perspective. Additionally, a brief online assessment could be a convenient way to receive recommendations tailored to your specific needs and goals. As scientific research into nutrition continues to progress, online resources are a valuable tool in navigating this important topic.