What You Should Know About Water-Soluble Vitamins

Vitamins are compounds that are essential to your body’s functioning. And at the highest level, they get categorized as either being fat-soluble or water-soluble. To keep your body functioning at peak performance, you need both kinds.

The fat-soluble vitamins are A, D, E and K.

Water-soluble vitamins are vitamin C and all the vitamins that start with the letter B (they’re known as the B-complex vitamins or just B vitamins). Water-soluble vitamins are important for your brain function, immune health, energy and more.

Family physician Matthew Goldman, MD, shares more about water-soluble vitamins and how to get the most out of these important nutrients.

Which vitamins are water-soluble?

There are nine water-soluble vitamins:

• Vitamin C.
• Vitamin B1 (thiamin).
• Vitamin B2 (riboflavin).
• Vitamin B3 (niacin).
• Vitamin B5 (pantothenic acid).
• Vitamin B6.
• Vitamin B7 (biotin).
• Vitamin B9 (folate).
• Vitamin B12.

Quick aside: Because we know your math brain is wondering where B4, B8, B10 and B11 are, right? Those compounds were at one time considered vitamins. But scientists and physicians now know they’re not really essential for health, so they lost their vitamin status. (Think of them like Pluto of the vitamin world.)

Dr. Goodman shares more about each of these essential nutrients.

Vitamin C

Vitamin C is probably one of the most famous out there. You likely already know about its role in your immune system. It’s also a powerful antioxidant. And it helps keep your skin and bones strong and healthy.

How much you should get

The U.S. Food and Drug Administration (FDA) recommends adults and children aged 4 and older get 90 milligrams (mg) of vitamin C each day.

Vitamin C foods

Oranges usually get all the credit for their high vitamin C content, but vitamin C is abundant in a number of fruits and veggies, not just citrus fruits.

Vitamin B1

Vitamin B1 also goes by the name thiamin or thiamine. It’s important for energy metabolism. It essentially helps turn the food you eat into energy to keep you going.

How much you should get

The FDA recommends adults and children over the age of 4 get 1.2 mg of vitamin B1 each day.

Vitamin B1 foods

Thiamin is found naturally in some animal products and grains. Some packaged foods may be fortified with thiamin as well.

Vitamin B2

Vitamin B2 (also called riboflavin) helps keep your blood and blood vessels healthy. That’s because it (along with some other B vitamins) helps regulate your levels of the amino acid homocysteine. Too much homocysteine can lead to blood clots or blood vessel blockages. Vitamin B2 helps turn homocysteine into other chemicals that your body needs.

How much you should get

The FDA recommends adults and children over the age of 4 get 1.3 mg of riboflavin each day.

Vitamin B2 foods

Some foods, particularly animal products, are naturally high in riboflavin. Some red meat, like steak and beef liver, contains high levels of vitamin B2. Eating too much red meat, however, has also been linked to conditions like cancer and heart disease. Aim for no more than one to two servings of red meat per week (6 ounces total per week, at most).

Vitamin B3

Vitamin B3 also goes by the name niacin. It helps regulate your cholesterol and blood pressure. It also helps support your brain and skin health.

How much you should get

The FDA recommends adults and children over age 4 get 16 mg of niacin each day.

Vitamin B3 foods

You’ll find high levels of niacin in certain meats, fish, rice and nuts.

Vitamin B5

Vitamin B5, also called pantothenic acid, helps make and break down fats.

How much you should get

The FDA recommends 5 mg of vitamin B5 daily for adults and children over the age of 4.

Vitamin B5 foods

The National Institutes of Health says vitamin B5 is present in almost all plant-based and animal-based foods. But certain foods contain higher amounts.

Vitamin B6

Vitamin B6 helps produce red blood cells. It also can protect your heart and even improve your mood.

How much you should get

The FDA recommends adults and children over the age of 4 get 1.7 mg of vitamin B6 each day.

Vitamin B6 foods

Vitamin B6 is commonly associated with animal products, grains vegetables and nuts.

Vitamin B7

Biotin is another name for vitamin B7. You may be most familiar with it as an ingredient in some hair, nail and skin care products.

Biotin’s effectiveness in your beauty routine is still up for debate. But we do know that it plays an important role in converting carbohydrates, fats and proteins into energy as part of your diet.

How much you should get

The FDA recommends adults and children age 4 and older get 30 micrograms (mcg) of biotin each day.

Vitamin B7 foods

Vitamin B9

Vitamin B9 is also called folate. It’s the vitamin most associated with prenatal vitamins. That’s because folate and folic acid are important for healthy fetal development during pregnancy.

But it’s not just for people who are pregnant. Vitamin B9 is also essential for forming red blood cells and DNA.

How much you should get

The FDA recommends adults and children age 4 and older get 400 mcg of folate each day. People who are pregnant are advised to get 600 mcg per day of folate.

Vitamin B9 foods

Unlike other B vitamins, B9 isn’t found in abundance in many foods. That’s why people who are pregnant or trying to conceive are recommended to take supplements to ensure they’re getting adequate amounts.

Vitamin B12

Vitamin B12 helps produce red blood cells, supports healthy brain function, gives you an energy boost and may even help keep your vision strong.

How much you should get

The FDA recommends adults and children age 4 and older get 2.4 mcg of vitamin B12 per day.

Vitamin B12 foods

How water-soluble vitamins work

Water-soluble vitamins dissolve in water. That means the water in your body absorbs these vitamins to put them to use.

Unlike fat-soluble vitamins, water-soluble vitamins don’t get stored in your body for long.

“Water-soluble vitamins move through your system quickly,” Dr. Goodman explains. “So, they need to be replenished frequently.”

That means it’s important to eat plenty of foods containing vitamins C and all the Bs regularly. That helps make sure you have enough of them circulating in your system.

And because they don’t stick around for long, it’s rare to have too much vitamin C or any of the B-complex vitamins in your system. What doesn’t get used just gets passed through your kidneys and leaves your body through your urine.

Foods vs. supplements

The best advice is to take a food-first approach to getting the nutrients your body needs, rather than relying on supplements. Whole foods have so many compounds that your body uses to keep healthy that supplements just can’t replicate as effectively.

But if you choose to take a supplement to ensure you’re getting enough vitamin C or B-complex vitamins, it’s safe for most people to do so, Dr. Goodman says.

That’s because, for most people, your body will rid itself of extra water-soluble vitamins. So, if you’re also getting vitamins from the food in your diet, supplements may mean you’re peeing out much of what you’re taking in. (Money literally down the toilet.)

If you’re concerned that you’re not getting enough water-soluble vitamins in your diet, talk with a healthcare professional, like a primary care doctor or a dietitian, about your intake and their advice.