Vitamins Field Guide: Definition, Types & Sources

Vitamins Field Guide: Definition, Types & Sources

Given how important we now know vitamins to be to our health—and the wealth of information available about these nutrients and their specific benefits—it may come as a surprise that the scientific community was still discovering the essential vitamins just some 75 years ago. In fact, though the term “vitamine” was coined around 1912, vitamin B12 wasn’t isolated until about 1947.1,2

Thankfully, what started as medical curiosity for physicians, chemists, and others in the 19th and 20th centuries has turned into a great understanding of nutrition and nutritional wellness. Of course, that doesn’t mean scientists have nothing left to learn about the role vitamins play in our lives and in keeping us healthy. Just like it doesn’t mean we don’t have room for improvement when it comes to meeting our daily vitamin needs. Surveys show a large number of Americans have inadequate intakes of certain vitamins.

Let’s explore vitamins, from how they’re defined and what makes them different from minerals to, importantly, how you can get more of them—from both food and supplements.

Vitamins Defined + How They Differ From Minerals

Broadly speaking, vitamins are defined as micronutrients that the body needs to function properly. The same can be said for minerals. But unlike minerals, which are inorganic elements found in soil and water, vitamins are organic substances made by plants and animals.

Vitamins are divided into two categories: fat-soluble and water-soluble. Those classified as fat-soluble dissolve, as you might guess, in fat and are thus more absorbable in the presence of dietary fat. They are stored in the body in our liver and fatty tissues, though insufficiencies or deficiencies are possible. Water-soluble vitamins, on the other hand, must dissolve in water before they can be absorbed and are therefore not stored (except for vitamin B12; more below). Excess amounts of these vitamins that aren’t used by the body are excreted through the urine. That means we need to consume them regularly to prevent insufficiencies or deficiencies.3,4

What Are the 13 Essential Vitamins & What Do They Do?

There are 13 vitamins we need to survive and stay healthy. And they all have different roles to play in keeping the body working as it should.4,5,6 

The Fat-Soluble Vitamins 

  1. Vitamin A: This vitamin is involved in eye health and vision plus immune function and more.
  2. Vitamin D: Known as the “sunshine vitamin,” since our bodies make it after sun exposure, vitamin D helps maintain healthy teeth and bones. It also plays a role in immune health.
  3. Vitamin E: A powerful antioxidant, it helps the body form red blood cells and helps other cells carry out their important jobs.
  4. Vitamin K: Often called the clotting vitamin, vitamin K helps blood coagulate. Studies suggest it helps maintain healthy bones as well as healthy arteries and a healthy heart.

The Water-Soluble Vitamins 

  1. Vitamin C: You likely know this potent antioxidant, also called ascorbic acid, plays a role in a strong immune system, but it also helps the body absorb iron, is a cofactor in the body’s synthesis of collagen, and is important to blood vessel and cardiovascular health.
  2. Vitamin B1 (thiamin): This B vitamin—one of the earlier recognized vitamins—helps the body turn carbohydrates into energy and contributes to healthy nerve cells, as well as a healthy nervous system overall.
  3. Vitamin B2 (riboflavin): Like the other Bs, riboflavin is involved in cellular energy and energy metabolism, as well as nerve function. It also aids in the creation of red blood cells.
  4. Vitamin B3 (niacin): Not surprisingly, it’s involved in changing food to energy and helping nerves to function, but it also plays a role in a healthy digestive system.
  5. Vitamin B5 (pantothenic acid): Aside from its similar work to the Bs above and below, pantothenic acid is also a precursor in the synthesis of coenzyme A, essential to many biochemical reactions in the body, including the production of fatty acids.
  6. Vitamin B6 (pyridoxine): No surprise, this vitamin helps the body maintain normal nerve function. It also helps the body make hemoglobin and break down proteins.
  7. Vitamin B7 (biotin): Like vitamin B5, biotin is involved in growth and helping the body break down and use food for energy.
  8. Vitamin B9 (folate/folic acid): Folate is important for red blood cell production and is critical during periods of rapid growth, which is why it’s especially important for pregnant women to get enough of this B vitamin.
  9. Vitamin B12 (cobalamin): B12 works with folate to help form red blood cells and is also important for energy metabolism and maintaining a healthy nervous system. Unlike the other water-soluble vitamins, it is stored in the body, mainly in the liver.

Sources of Vitamins

A healthy, varied diet is abundant in the 13 essential vitamins. Not surprisingly, fresh produce is a great source of a number of both types of vitamins. Dark green vegetables—broccoli, brussels sprouts, asparagus, and spinach plus other leafy options like kale and lettuce—for example, are rich in vitamins A, B5, B9, C, E, and K. Citrus fruits are well-known sources of vitamin C; other fruits offer up vitamin E (papaya and mango) and B6 (banana) in spades.4,7

Lean meats, fish, eggs, dairy, legumes, and whole grains are also good sources. For instance, fatty fish such as salmon and mackerel naturally contain vitamin D, while other fish like tuna deliver B3. Eggs contain vitamins A and K and many B vitamins, including B12. Legumes and whole grains are also rich sources of B vitamins. Fortified milk and dairy products can help you meet your requirements for vitamins A and D; soymilk is often fortified with B12 to help vegetarians and vegans get enough of this vitamin, since it is only found naturally in animal products. 4,7   

Of course, you can also find these vitamins in vitamin supplements, including multivitamins. Keep reading to discover if supplementation might be right for you.

Common Vitamin Deficiencies & Insufficiencies

Though a balanced diet as described above can deliver the daily vitamins you need, studies suggest the majority of Americans simply aren’t eating enough fruits, vegetables, and whole grains.8 The reality of our standard diet and our busy daily lives means that sometimes food alone is not enough.

Specifically, research indicates a whopping 94% of the population doesn’t meet the daily requirement for vitamin D, 88% isn’t getting enough vitamin E, 43% has inadequate intakes of vitamin A, and just shy of 40% is low on vitamin C. While a daily limit isn’t set for vitamin K, the same research suggests nearly 67% of Americans have less than ideal intakes of this nutrient.8

As mentioned above, the body synthesizes vitamin D from sunlight. Although fortified foods and fatty fish offer vitamin D, it is difficult to get enough vitamin D just from diet. Regular moderate sun exposure is important for maintaining healthy levels. Supplements can also help, especially if you live in certain latitudes, where the skin is unable to produce little if any vitamin D most of the year.

Vitamin Supplements: Benefits & The Best Time to Take Them

Vitamin supplements can’t take the place of nutritious foods. But they can be an important addition to a healthy diet, working in tandem with food to help you better find nutritional balance and stay feeling your best.*

Keep in mind that the FDA established the Recommended Daily Intake (RDI) and Recommended Daily Allowance (RDA) for vitamins and minerals to help us all attain a minimum level of nutrition to support basic physiology. You want to ensure you’re meeting these levels each day, and supplements can help close the gap between what you’re getting through your diet and the amounts needed for overall wellness. But often, for our bodies to function optimally, studies support higher levels of some nutrients. In those cases, supplements can help sustain amounts required for peak performance.

If you aren’t getting enough vitamins from your diet or want to get more of a particular nutrient than can be easily consumed through food, a vitamin supplement could be a good option for you. You can find single-vitamin supplements or vitamin combinations, including multivitamins, which may also contain minerals and herbs.

When Is the Best Time to Take Vitamins?

Generally, the best time to take supplements is whatever time is easiest for you, so they become a natural addition to your daily routine. After all, you can only obtain their benefits if you remember to take them. That said, here are some helpful reminders.

Some vitamins are water-soluble. Thus, it’s advised to take these supplements with a glass of water, usually on an empty stomach. Since fat-soluble vitamins need fat for absorption, the best time to take these vitamins is after you’ve eaten a snack or meal that contains fats. Because most multis contain both types of vitamins, you may most benefit from taking yours with a meal or small bite of food and a glass of water. Experts typically suggest taking multivitamins with your breakfast. Though, again, it really comes down to personal preference and your specific schedule.

Solaray Vitamins & Multivitamins

Solaray is proud to offer an array of vitamin supplements in different formats to meet your needs. Like all of our products, our vitamin and multivitamin formulas are triple tested for purity and potency at our state-of-the-art lab in the beautiful mountains of Utah.

How powerful are they? Take our timed-release Vitamin C 1000 mg, as an example. As our Food Is Not Enough campaign illustrates, you would need to eat a dozen oranges or 133 strawberries to get the same daily immune support found in just one capsule.*

You can shop our website by vitamin, including Vitamin C formulas to support a healthy immune systems; our Vitamin D supplements for bone + immune support, including best-selling Vitamin D3 + K2; and our B Vitamins Collection, which offers B-complex formulas featuring all eight B vitamins for energy, red blood cell, and nerve function support.*  

We also offer multivitamins, including our revolutionary Liposomal Multivitamins made with advanced liposomal absorption technology. Liposomes have a unique structure that allows them to encase vitamins in a protective barrier, helping the nutrients survive digestion to reach and be used by cells.*

In total, we offer more than 70 vitamin supplements. Shop all vitamins here

Valuable Vitamins: Health Essentials

The 13 essential vitamins have their own individual jobs to do, with them all playing vitally important roles in human growth and functioning. With the exception of vitamin D, these nutrients aren’t produced by the body and must come from diet along with supplements when appropriate. Unfortunately, many Americans don’t get enough vitamins from food alone. Vitamin supplements can help fill in any naturally occurring nutritional gaps and ensure your bases are covered. Solaray vitamin supplements include offerings of all 13 essential vitamins plus multivitamin formulas to help support nutritional balance and overall health and well-being.*



  1. Richard D. Semba, “The Discovery of the Vitamins,” International Journal for Vitamin and Nutrition Research 82, no. 5 (2012),
  2. “The Vitamin B Complex,” National Historic Chemical Landmarks, American Chemical Society,
  3. “Vitamins and Minerals,” The Nutrition Source, Harvard T.H. Chan School of Public Health,
  4. “Vitamins,” Medical Encyclopedia, MedlinePlus, National Library of Medicine,
  5. “Vitamins,” Linus Pauling Institute Micronutrient Information Center, Oregon State University,
  6. “B Vitamins,” The Nutrition Source, Harvard T.H. Chan School of Public Health,
  7. “The Best Foods for Vitamins and Minerals,” Harvard Health Publishing, Harvard Medical School, August 17, 2021,
  8. “Micronutrient Inadequacies in the US Population: An Overview,” Linus Pauling Institute Micronutrient Information Center, Oregon State University,

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