"How can I make sure I'm getting my vitamins?" is actually a very loaded question. The answer? It depends on who you ask.
If you're talking to someone hawking supplements, they're going to tell you about the latest nutritional miracle and may not even answer your question. A traditional MD might just plainly direct you to buy a bottle of multivitamins and quit worrying about it, while a registered dietician might start listing from their encyclopaedic vegetable knowledge, confusing you in the process.
It's hard to get a straight answer. This is partly because experts don't know the exact answer and the science of nutrition it constantly changing as researchers try to figure it all out.
What we do know, however, is that there are 13 essential vitamins, so named because your body truly could not function without them. These compounds keep your heart pumping, your cells growing, and your food digesting. Without them, people develop old-timey-sounding conditions including scurvy (vitamin C deficiency), anaemia (iron deficiency), and rickets (vitamin D deficiency).
We also know quite a bit about each one of the vitamins' basic properties. Some vitamins are fat-soluble, such as vitamin D, meaning your body can store excess amounts of them. But others, such as the B vitamins, are water-soluble, meaning that you'll just pee out the excess, rather than stocking up. Luckily (as you'll see in this article), it's pretty easy to get everything you need just by eating a balanced, healthy diet and going outside every once in a while.
That's why most of us don't need to take vitamin supplements at all. You also don't need to be taking extra amounts of these compounds. For instance, despite the hype, a megadose of vitamin C will not prevent a cold. In fact, if you consistently take too much, you can actually overdose on vitamins and have a dangerous reaction to some. That said, there are instances when certain supplements become necessary.
Ahead, we clear all this up with a guide to each single essential vitamin. Click through to learn what each vitamin does for you and where to find 'em.
Vitamin A (Retinol)
Why you need it: Vitamin A helps keep many of your organs working properly, including your kidneys, heart, and lungs. It's also necessary for maintaining healthy teeth and skin. It's especially important for vision.
People with vitamin A deficiencies have trouble seeing in low light. And vitamin A deficiency is the leading cause of preventable blindness worldwide.
Photographed by Eric Helgas.
Where you'll find it: Many animal products have vitamin A, including cheese, eggs, and meat. But because these also come with high levels of saturated fat and cholesterol, these shouldn't be your main sources of the vitamin. Instead, focus on eating your leafy greens as well as red and yellow fruits and vegetables (e.g., mangoes and carrots).
Photographed by Ingalls.
Vitamin C (Ascorbic Acid)
Why you need it: Your body needs vitamin C to repair itself. That includes making collagen, a protein you need in order to heal wounds, as well as keeping your teeth, bones, and cartilage in good shape. Plus, vitamin C can help your body absorb iron from other foods.
Photographed by Ruby Yeh.
Where you'll find it: We often think of citrus fruits as the ultimate vitamin C sources — and they're definitely good choices. But other foods (including potatoes, tomatoes, and broccoli) pack a big vitamin C punch, as well. Some cereals are also fortified with extra vitamin C, so be sure to check the label.
Photographed Danny Kim.
Vitamin D
Why you need it: Vitamin D helps your body absorb calcium and you need both to keep your bones healthy. As a kid, vitamin D was especially important to make sure your skeleton grew with you properly. But you still need it as an adult. Vitamin D deficiency can make you feel especially fatigued and lead to conditions like osteoporosis as you get older.
Photographed by Refinery29.
Where you'll find it: Very few foods contain vitamin D (and those that do, such as milk and orange juice, are fortified, meaning vitamin D was added). Humans get most of our vitamin D from sun exposure, the original source.
When you're exposed to UV rays, your skin converts a hormone into D3, a form of vitamin D that we can't readily use. That then gets sent to your liver and kidneys, which turn it into the active form of vitamin D.
Photographed by Erin Phraner.
Isn't everyone deficient in vitamin D?
Yes and no. There are reports that vitamin D deficiency has been increasing rapidly in the past decade or so. But the exact cutoff for a deficiency has made this a little confusing. Some medical organisations believe that you're insufficient below 20 ng/ml while others start counting insufficiency below 30. However, everyone agrees that anything below 10 ng/ml is definitely worrying.
Your doctor can order a blood test during a regular check-up if you're concerned about your vitamin D levels. If they're low, she can suggest a course of supplements to help boost them.
Photographed by Lauren Perlstein.
Vitamin E
Why you need it: Your immune system needs vitamin E in order to keep you safe from viruses and bacteria. It also helps you use vitamin K (more on that later). Vitamin E is also an antioxidant, which means it helps protect the body from damage to tissues and organs caused by free radicals. These are molecules that are thought to play a role in the ageing process. However, researchers are still figuring out exactly how helpful antioxidants are (if at all).
Photographed by Andy Price.
Where you'll find it: There are actually several different antioxidant compounds all referred to collectively as "vitamin E." You'll find them in the highest amounts in seeds, nuts, and vegetable oils. But they're also in avocado and dark-green veggies.
Photographed by Molly Cranna.
Vitamin K
Why you need it: Vitamin K's role is simple and vital. Without it, your blood wouldn't clot. People who have conditions in which the blood doesn't clot properly, such as haemophilia, bleed longer after an injury than others and may suffer from internal bleeding. That can damage your organs and even be life-threatening.
Photographed by Amelia Alpaugh.
Where you'll find it: Dark leafy greens are your best bet for getting vitamin K. However, soybeans, pumpkin, eggs, and meats are also good options.
Photographed by Nicholas Bloise.
Vitamin B1 (Thiamine)
Why you need it: Thiamine is especially helpful for converting carbohydrates into usable energy — glucose. Your body, brain, and nerves need that to function normally.
Photographed by Eric Helgas.
Where you'll find it: Get your hands on some whole grains, legumes, eggs, nuts, and seeds and you'll be all set. A hearty grain bowl is the perfect way to get all of 'em in one meal.
Photographed by Danny Kim.
Vitamin B2 (Riboflavin)
Why you need it: Like all B vitamins, riboflavin helps your body convert carbs, proteins, and fats into energy that you can use. But riboflavin deficiency has also been linked to vision problems and migraines. Researchers are still figuring out exactly what that association means.
Photographed by Nicholas Bloise.
Where you'll find it: The best sources of riboflavin are lean meats, dairy (including milk), and eggs. But you can also get it from leafy veggies, legumes, and nuts.
Photographed by Ted Cavanaugh.
Vitamin B3 (Niacin)
Why you need it: Niacin helps the other B vitamins create energy in the body. It's also necessary for keeping the digestive system, nerves, and skin healthy. Plus, it also helps your circulation and can keep inflammation in check. In the U.S., the most common cause of niacin deficiency is alcoholism.
Photographed by Eric Helgas.
Where you'll find it: Fish is one of the best sources of niacin, especially salmon and tuna. Other great options include avocados, nuts, and legumes.
Photographed by Phoebe Chuason.
Will it help me study?
There are plenty of internet anecdotes out there claiming that taking niacin supplements helps brain function, including memory enhancement. (Even Scientology founder and all-around weirdo L. Ron Hubbard was into the stuff.)
There is preliminary evidence to suggest that people who take niacin are less likely to develop Alzheimer's, a memory-related illness. But there's no research to suggest that niacin will turn you into a superhuman study machine if you're already getting the amount you need.
Photographed by Eric Helgas.
Vitamin B5 (Pantothenic Acid)
Why you need it: Pantothenic acid aids in the production of stress- and sex-related hormones in your adrenal gland. It also helps you make cholesterol, which your body needs to produce hormones, vitamin D, and a few other compounds. Plus, pantothenic acid keeps your digestive system humming along.
Photographed by Janelle Jones.
Where you'll find it: Luckily, you can get pantothenic acid from a bunch of different healthy food sources. That includes egg yolks, sweet potatoes, poultry, avocados, legumes, lentils, and leafy greens.
Photographed by Winnie Au.
Vitamin B12
Why you need it: B12 helps your body create healthy red blood cells, regulate neurological functioning, and synthesise DNA. Plus, along with the other B vitamins, B12 helps metabolise food into energy.
Photographed by Nicholas Bloise.
Where you'll find it: There's not much B12 naturally occurring in plant foods, unfortunately. So animal products (and fortified plant-based foods) are the only sources other than supplements. Besides meat, the best places to turn are dairy products and eggs.
Photographed by Eric Helgas.
Fun fact: It's actually made by bacteria.
B12 is somewhat unique in the fact that animals and plants can't actually make it. Instead, that task falls to bacteria and a class of microorganisms called archaea. So even though you can get it from meat, it's really being made by bacteria present in that meat. Yum?
Photographed by Ingalls.
Vitamin B7 (Biotin)
Why you need it: Also sometimes called "vitamin H," biotin is actually another helpful B vitamin. It helps keep you skin, nails, hair, and eyes healthy. Biotin is often advertised on cosmetic products for its potential hair- and nail-strengthening powers, but there's not much conclusive evidence that getting any more biotin than you need is going to help there.
Photographed by Amelia Alpaugh.
Where you'll find it: Biotin is in many of the same foods that contain pantothenic acid, including egg yolks and legumes. But it's also found in nuts and seeds as well as cauliflower, mushrooms, bananas, and whole grains. Oh, and it's in chocolate.
Photographed by Andy Price.
Vitamin B6 (Pyroxidine)
Why you need it: Pyroxidine does a lot within the body — it's involved in over 100 enzyme reactions — but mainly, it's focused on converting protein to energy. It also helps create a few neurotransmitters that your brain relies on, including serotonin and norepinephrine.
Photographed by Ruby Yeh.
Where you'll find it: The best sources of pyroxidine include veggies, lean meats, and non-citrus fruits.
Photographed by Amelia Alpaugh.
Vitamin B9 ( Folic Acid)
Why you need it: Folic acid is especially important for brain functioning and mental health. Low levels of folic acid have been linked to depression, memory issues, and irritability. It also helps build DNA, tissues, and red blood cells.
Photographed by Molly Cranna.
Where you'll find it: Dark leafy greens, especially spinach, should be your first stop for folic acid. But you can also get it by eating legumes and citrus.
Photographed by Shirley Yu.
Why is folic acid so important during pregnancy?
Pregnant women (and those who are trying to become pregnant) are recommended to increase their daily intake of folic acid. That's because it's even more crucial to get enough B9 early in your life when you're growing quickly — like when you're in the womb. Otherwise, folic acid deficiency can lead to two serious birth defects.
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