A group of 13 organic compounds make up two types of vitamins that your body needs for normal cell function, development and growth. Each of the vitamins has important roles, including providing energy, maintaining bones, healing wounds, chemical messaging and boosting your immune system.
Amount of Vitamins You Need
Essential vitamins cannot be synthesized by your body, so you need to eat a balanced diet that includes sources of vitamins in fruits, vegetables, beans, lentils, whole grains and dairy foods. Vitamin supplements and fortified foods may also help you get a sufficient amount of vitamins to prevent health problems, including heart disease, cancer and osteoporosis, according to MedlinePlus.
Dietary Guidelines for Americans lists recommended amounts of vitamins you need for optimal health. These nutritional goals depend on age and gender. The average amounts required for adults between the ages of 31 and 50 years are:
Vitamin A —
900 milligrams for men; 700 milligrams for women
Vitamin E —
Vitamin D —
600 international units
Vitamin C —
90 milligrams for men; 75 milligrams for women
Thiamin (B1) —
1.2 milligrams for men; 1.1 milligrams for women
Riboflavin (B2) —
1.3 milligrams for men; 1.1 milligrams for women
Niacin (B3) —
16 milligrams for men; 14 milligrams for women
Pantothenic acid (B5) – 5 milligrams
Vitamin B6 —
Biotin (B7) —
Folate (B9) —
Vitamin B12 —
Vitamin K —
120 micrograms for men; 90 micrograms for women
The above vitamins list is grouped into two types — water-soluble and fat-soluble vitamins.
There are nine water-soluble vitamins that include the B vitamins and vitamin C. Water-soluble vitamins are packed into the watery portions of food and are not stored by your body after digestion. Excesses are eliminated in your urine, with the exception of vitamin B12, which can be stored in the liver, according to MedlinePlus.
When it comes to the uses of vitamins, the B group of water-soluble vitamins are the ones necessary to help free the energy from the food you eat to fuel your body and keep it functioning properly. A closer look at the group of water soluble B-complex vitamins and their functions shows just how important they are to your health:
- Thiamin — essential for energy metabolism to assist with the
growth, development and functioning of cells in your body. In addition to
fortified foods, the best natural food sources
of thiamin are from whole grains and meat, especially pork.
- Riboflavin — helps break down the proteins, fats and
carbohydrates from food to supply energy to your organs. Riboflavin helps your
body absorb nutrients needed to maintain tissue. Good food sources of vitamin B2 include eggs, organ meats, lean meats and milk.
- Niacin — is also used by your body to turn food into energy.
Niacin helps maintain the health of your skin, brain, spinal cord, sensory organs and gastrointestinal system. Foods rich in niacin include yeast, milk, meat and cereal grains.
- Pantothenic acid — important for digesting fat in your body. Although
almost all plant and animal foods contain pantothenic acid, some of the best sources of the vitamin are from
meat, including organ meat, whole grains, some vegetables and fortified
- Vitamin B6 — contains coenzymes that help break down macronutrients
for use in your body to support your immune system and brain health. An adequate
blood level of vitamin B6 may be linked with a reduced risk of cancer, says the Harvard T.H. Chan School of Public Health.
In addition, vitamin B6 has been used to help relieve nausea during pregnancy. Top sources of vitamin B6 are beef liver,
fish and fortified cereal foods.
- Vitamin B12 — needed for
the formation of red blood cells and DNA. It also plays a key role in the function and
development of your nervous system and brain. A lack of vitamin B12 can cause an increase in homocysteine levels, which are associated with a risk of heart disease. Animal products, including fish, liver, red meat and dairy products, are the only natural source of vitamin B12.
- Biotin — helps metabolize carbohydrates, fats and proteins into energy required for many cellular functions. In addition, biotin is important for healthy hair, skin and nails. High protein foods, such as meat, fish and eggs, contain
biotin, says National Institutes of Health. Seeds, nuts and some vegetables are also a good source of the vitamin.
- Folate — helps with the formation of DNA and RNA and is needed for protein metabolism, advises Harvard T.H. Chan. Folate is best known for its role in fetal growth and development, including the prevention of neural tube birth defects. The supplemental form of folate is folic acid, which is actually better absorbed than folate from food sources. In addition to fortified grain products, beef liver, vegetables and dark green leafy vegetables are among the best sources of vitamin B9.
Vitamin C is another water-soluble vitamin that your body needs, especially to support your immune system. One of its roles is to help make collagen, a fibrous protein in connective tissue that your body uses to maintain bone, cartilage and blood. Collagen helps to heal wounds, forms the base for teeth and bones and maintains blood vessel walls, says Harvard T.H. Chan.
The best food sources of vitamin C come from fruits and vegetables. Citrus fruits are highest in vitamin C but bell peppers, strawberries and tomatoes also contain vitamin C.
Although water-soluble vitamins should be replenished in your body every few days, be aware of the small risk from consuming too much from supplements. For example, very high doses of vitamin B6 over the recommended amount can damage nerves, causing numbness and muscle weakness, according to "Making Sense of Vitamins and Minerals," published by Harvard Health in 2019.
Too much niacin from supplements can result in an overdose with symptoms including skin flushing combined with dizziness, nausea and vomiting, diarrhea and gout.
There are four fat-soluble vitamins, which are vitamins A, D, E and K. These vitamins need to be escorted by proteins that act as carriers in order to be distributed throughout your body, according to the "Making Sense of Vitamins and Minerals" article. Excess amounts of fat-soluble vitamins are stored in your liver and fat tissue to be released as needed.
Some of the fat-soluble vitamins are the types of vitamins that help your immune system, which is needed to fight off invading bacteria and viruses. Fat-soluble vitamins keep your eyes, lungs, digestive tract, nervous system and bones healthy.
Taking a more detailed focus on the fat-soluble vitamins and their functions can give you an idea of how necessary they are to maintain your overall health.
- Vitamin A — helps with the formation and maintenance of
bones and helps your organs, such as eyes, heart, lungs and kidneys, function
properly. Some foods are fortified with vitamin A, but the best natural food
sources come from organ meat, fish and green leafy vegetables, says the National Institutes of Health.
- Vitamin D — is best known for its role in maintaining strong
bones. Vitamin D helps with the absorption of calcium from food and supplements. Your muscles need vitamin D to move and
your nerves need it to carry messages from your brain to every cell in your
body. Besides getting vitamin D from the sun and from fortified foods, fatty
fish are the best natural sources of vitamin D.
- Vitamin E — helps to widen blood vessels and
keep blood from clotting. As an antioxidant, vitamin E may help protect you
from diseases related to aging. Your cells need vitamin E in order to interact
with each other to carry out many important functions. The best sources to
meet your vitamin E requirements are from vegetable oils, nuts and seeds, green
leafy vegetables and fortified foods.
- Vitamin K — is needed for making proteins required by your bones and tissue. It is also responsible for the ability of blood to clot so you don't bleed too much. Green leafy vegetables and dark berries are among the best food choices for vitamin K.
Due to the ability of fat-soluble vitamins to be stored in your body, toxic levels can result from a build up. Although it’s very rare to get too much of a vitamin just from food, taking too many supplements may result in negative effects to your health.
- MedlinePlus: "Vitamins"
- Health.gov: "Dietary Guidelines for Americans, 2015-2020: Appendix 7. Daily Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations"
- National Institutes of Health: "Pantothenic Acid"
- National Institutes of Health: "Biotin"
- National Institutes of Health: "Thiamin"
- National Institutes of Health: "Riboflavin"
- Mayo Clinic: "Niacin"
- Harvard T.H. Chan School of Public Health: "Vitamin B6"
- Harvard T.H. Chan School of Public Health: "Vitamin B12"
- Harvard T.H. Chan School of Public Health: "Folate (Folic Acid) – Vitamin B9"
- Harvard T.H. Chan School of Public Health: "Vitamin C"
- Harvard Health: "Help Guide: Vitamins and Minerals"
- Mayo Clinic: "Niacin Overdose: What Are the Symptoms?"
- National Institutes of Health: "Vitamin A"
- National Institutes of Health: "Vitamin D"
- MedlinePlus: "Vitamin E"
- MedlinePlus: "Vitamin K"