Things You Should Know Before You Start Taking Vitamins

We eat food all day — from the coffee and muffin we wolf down as we're driving to work in the morning, to the salad or sandwich we devour at our desk or during a lunch break, to the steak dinner that we sit down to in the evening — we're constantly consuming calories, vitamins, and nutrients for our bodies to function. Despite this, many of us believe that vitamin and mineral supplements should be a daily part of our diet.

But are they as necessary as some of us believe? The Mayo Clinic says that might not be the case. The Dietary Guidelines for Americans outline the importance of getting most of our nutritional needs from the food that we eat, as the nutrition contained in whole foods has a few significant differences in comparison with synthetically derived vitamins. The Mayo Clinic says there are three major reasons why whole foods present vitamins better: The nutrition whole foods provide is more complex, whole foods also contain fiber, and whole foods contain phytochemicals, which may help protect against cancer, heart disease, diabetes, and high blood pressure.

Sometimes, though, whole-food nutrition may not be as readily available. Or maybe your body struggles to obtain a certain vitamin naturally. Maybe your current diet just doesn't support all of your needs. In these cases, there are a few questions you should be asking yourself before starting a vitamin regimen.

Are there essential vitamins we need?

Human bodies have nine essential vitamins and minerals that we need on a daily basis. We can get all nine of these simply from our diets — if we eat a balanced and healthy one. These essentials include vitamins A, B, C, D, E, and K, as well as calcium, iron, and zinc. Vitamins A, D, E, and K are fat-soluble, which means they are similar to oil and do not dissolve in water as the rest do (according to Healthline). Our bodies can thus potentially store up vitamins A, D, E, and K, but water-soluble vitamins are excreted with excess water from our bodies every day.

Before you jump to look for a multivitamin that contains all these, remember that most of us can get these simply from eating a balanced diet, per the Cleveland Clinic. Healthline lists butter and egg yolks as common sources of vitamin A. Liver-based products such as fish liver oil and liverwurst are very high in vitamin A, but they're not a typical food in most of our diets.

Fish liver oil is also a good source of vitamin D, as are salmon, egg yolks, mushrooms, as well as fortified dairy products (per Healthline). Vitamin E is found mostly in nuts and seeds, particularly sunflowers, almonds, and hazelnuts. Vitamin K is present in leafy greens such as parsley, kale, and spinach (via Healthline).

Do I even need vitamin supplements?

Only about 50% of Americans take a multivitamin or some kind of supplement, but the populations that should definitely be considering them include anyone over the age of 65, pregnant individuals, those with malabsorption conditions, and those on certain medications (per Harvard School of Medicine). Older populations can have difficulty chewing or swallowing food, or can have a suppressed appetite from certain medications or even loneliness (per Harvard). Pregnancy will also require higher nutritional inputs, and certain vitamins such as folate, B vitamins, iron, calcium, vitamin D, and DHA are important to have in a prenatal vitamin. Malabsorption disease, such as celiac disease, will mean that vitamins are not as readily absorbed from food, and certain medications can also interfere with this absorption. 

The Harvard School of Medicine also makes sure to include a note on vitamin D and supplemental needs for certain populations. Since vitamin D is not naturally occurring in many foods, dairy products are usually fortified with it, but this can pose a problem for those abstaining from dairy. Also, populations living in areas with fewer days of full sun can have lower levels of vitamin D, as well as individuals with darker skin, since the extra melanin acts to block the sun's rays that develop the vitamin D in our skin (via Harvard).

If you fall into one of these populations, it can be a good idea for you to take some kind of supplements to counteract the imbalance.

Can vitamins substitute for a poor diet?

No! Doctors urge over and over again to first take a good look at your diet and make sure that you're getting as much as possible from food sources. Our bodies are just better equipped to extract vitamins from food sources, so your diet should always be evaluated first before a doctor recommends a supplement, says Dr. Jacob Hascalovici in Eat This, Not That. Plus, everyone's body fluctuates over time in terms of nutritional needs, so a doctor is best equipped to help you determine what you need to supplement.

Diseases caused by lack of nutrients are rare in the United States and will likely not be a cause of concern for most of us. On the other hand, too much of a particular vitamin or mineral can have adverse effects on your body over time, and can lead to worse health than you started out with. Dr. Hascalovici advises a diet rich in a wide range of fruits, vegetables, whole grains, lean meats, and low-fat dairy (per Eat This, Not That).

Sometimes though, even a complete diet can not make up for certain deficiencies. To top it off, certain issues like poor sleep or being overly stressed can make it hard for your body to absorb nutrients from a complete diet, says nutritionist Dawn Lerman, MA, CHHC, LCAT, AADP to Healthline. Those are the cases when taking a multivitamin or a targeted vitamin can help.

Should I take individual or multivitamins?

Despite there being oodles of multivitamins on the market, taking your vitamins together is not necessarily a good thing. The combination of both fat-soluble and water-soluble vitamins means that either one or the other will not be performing at its best, depending on when you take the multivitamin, according to Consumer Lab. This is because fat-soluble vitamins are best absorbed by the body when they're taken in combination with some fat, ideally, at a meal. Water-soluble vitamins, on the other hand, are best absorbed when taken on an empty stomach and with just a glass of water.

Also, some vitamins or minerals compete with each other. Consumer Labs gives the example of calcium and magnesium, both of which are taken in relatively large doses and will overpower the others. Therefore, these minerals are best taken separately. Large doses of fat-soluble vitamins will also compete with other fat-soluble vitamins, so if your body needs more than one, they will not both be absorbed.

Largely, it comes down to if you are just wanting to supplement a poor diet or if you have some kind of targeted need. Dr. Ruscio, a Doctor of Natural Medicine based in Texas, says that the bottom line of multivitamins versus individual vitamins is that multivitamins will fill in gaps left from a poor diet, while individual vitamins can be taken in higher quantities and are better suited for those that need targeted approaches.

When is the best time to take vitamins?

Most vitamins can be taken at any time of day, but their form of absorption — water- or fat-soluble — will determine just how much of a vitamin your body absorbs and uses. If you're going to be taking a multivitamin, determine which vitamins are most important to your body and take them accordingly. Or alternate between taking them on an empty stomach and with a meal if your body isn't averse to them on an empty stomach.

For individual vitamins, there are a few guidelines. For example, the Cleveland Clinic suggests taking vitamin B-12 in the morning, as it has energizing properties and is water-soluble. It can also be taken with vitamin C in the morning. Another mineral that must be more closely watched in the quantities and the time it is taken is calcium. It depends on the kind you're taking: Calcium carbonate should be taken with a meal, while calcium citrate is more easygoing and can be taken with or without (per Cleveland Clinic).

The Cleveland Clinic also says fat-soluble vitamins — A, D, E, and K — should be taken with a meal that contains some fat. A lot is not necessary so even some full-fat yogurt or milk will do the trick. Even so, Consumer Labs' suggestion is to take vitamin D with dinner or your biggest meal of the day, as it usually contains more fat and can increase absorption by as much as 50%.

Do people of different genders require different vitamins?

Men and women biologically need different vitamins and in different quantities — even age plays a role in how much of a vitamin you need. GNC states that even the Recommended Dietary Allowance demonstrates the different needs between biological males and females. Not only is biology a factor, but men and women tend to have different nutritional needs at different times of their lives.

For instance, women lose bone mass density faster than men, so they might need a supplement for calcium more than a man of the same age does (per GNC). Dr. Josh Axe D.N.M., C.N.S., founder of Ancient Nutrition, tells Vitamin Shoppe that other vitamins women tend to be lower in are iron, zinc, and vitamin B12. On the other hand, he explains that men will benefit from supplements with zinc and selenium, as those nutrients are beneficial to men's immune systems and sexual function.

Are vitamins regulated and safe?

The Federal Drug and Food Administration (FDA) does not regulate vitamins, and thus each consumer must do their own due diligence when it comes to picking vitamin sources. CNET warns consumers that the FDA still regulates supplements based on the Dietary Supplement Health and Education Act of 1994, which really just has one stipulation for products: "Manufacturers and distributors of dietary supplements and dietary ingredients are prohibited from marketing products that are adulterated or misbranded."

Once a product hits the market, the FDA can regulate it and determine if it is safe or not, but by that time consumers might have already ingested potentially harmful products (per CNET). To make sure that you're getting a product that is safe and has been rigorously tested by third parties, look for a few different labels when you're shopping for vitamins.

First, look for the United States Pharmacopeia (USP) seal of approval on the bottles (per Harvard School of Public Health). This seal ensures the ingredients are what they are supposed to be in the quantities that the bottle specifies. Secondly, the National Sanitation Foundation (NSF) certification tells you that the contents of the bottle you're buying have been tested and approved by a third-party agency for food and supplements (per CNET). Thirdly, CNET says to also keep an eye out for the Good Manufacturing Practices (GMP) certification. This is the FDA-regulated certification and lets you know that the product has passed the guidelines for production standards.

Can I take vitamins with my medications?

One of the most important things to be aware of when considering supplementation is if you're taking any other kind of medication at the same time. Some vitamin supplements can interfere with how medications work and can even nullify your medication's effects. Dr. Jae Pak, M.D., of Jae Pak Medical, tells Eat This, Not That, "Another thing many don't consider when taking vitamins and supplements is that they could interact with other medications and supplements you're taking. They may also have harmful side effects in addition to any perceived benefits. For these reasons, it is important to consult with a trusted health care provider before beginning any vitamin or supplement regimen."

For instance, Livestrong warns those that take blood-thinning medication that taking high doses of vitamin K or C can interfere with their medication and cause blood clots. Similarly, Livestrong cautions that high doses of B3 can lead to dangerously low blood pressure for those taking blood pressure medication already, and that vitamin D can interfere with digitalis-based drugs to induce arrhythmia or irregular heartbeat.

Is there a difference between generic and name-brand vitamins?

There is not much of a difference in most instances between generic vitamins and those that are branded for a specific company. Instead of looking for a name brand, check the labels for certifications and the listed amounts of each vitamin to know whether a brand or a certain vitamin is legitimate, according to CNET.

Even better, CNET says to check for a nutritional label instead of a supplement fact label. Nutrition labels make the product a food product, which means the FDA must evaluate it and deem it safe for sale and consumption, so you have an extra layer of protection. Your best possible scenario would be a nutrition label coupled with an NSF certification, a USP-verified mark, and a GMP certification (per CNET).

The Cleveland Clinic also says to be wary of vitamin supplements that claim certain things or "guarantee" results. These kinds of supplements might well have added ingredients that are not necessary or use too high doses of a vitamin, which could lead to vitamin toxicity (more on that later).

Are personalized vitamins worth it?

Everyone is unique in their diet, exercise habits, and overall lifestyle, and thus personalized vitamins might seem like a great way to fill in any gaps that you might have in your nutrition. In recent years, many personalized vitamin companies have popped up. Some are better than others — some companies personalize your vitamin needs simply by asking you a few questions about your lifestyle, while others use a virtual or in-person consultation with a nutritionist. The company Nutrigenomix, for instance, created a test for individuals based on nutrigenomics as "evidence shows that one-size-fits-all nutrition recommendations are inefficient and often ineffective" (per Nutrigenomix).

Harvard School of Public Health says that it's a good idea to consult with a nutritionist so that they can evaluate your current diet and give you a better idea of what vitamins you might need to supplement — and which ones you don't need. This is the best way to get "personalized" vitamins, as your nutritionist will also be able to recommend vitamin supplements that are trusted by doctors.

What happens if I take too many vitamins?

Vitamin toxicity is a real thing, and it can cause all sorts of trouble in your body. Generally, it is fat-soluble vitamins that can build up and cause toxicity, as they are stored in our livers while water-soluble vitamins get flushed out every day. Symptoms of vitamin toxicity can include diarrhea, irregular heartbeat, hair loss, and joint pain, according to Healthline.

Vitamin toxicity can happen even if you're not taking supplements by the handfuls: Even just eating a nutrient-dense diet and taking a multivitamin can put you over the limit for certain vitamins in your daily intake (per Healthline). Healthline gives a few examples of people who need to be wary of their vitamin intake — smokers and pregnant individuals should not take multivitamins with large amounts of vitamin A, and men need to be cautious about multivitamins with large amounts of iron, as they store more of it than women do. Those who have hemochromatosis (build-up of iron in the body) also need to be cautious, as not only will they hold excess iron, but the toxicity of the mineral can lead to liver cirrhosis, cancer, and heart disease. Vitamin C is also equally off-limits to those that suffer from hemochromatosis.