PlayInfoBox

Home /Education /Vitamins and What They Actually Do

Vitamins and What They Actually Do

Each vitamin has a distinct job in the body, and knowing roughly what each one does makes food labels and dietary advice much easier to follow.

Vitamin A

Supports vision (especially in low light), immune function, and skin health. Found in liver, eggs, and orange or dark leafy vegetables like carrots, sweet potatoes, and spinach.

B vitamins (B1 through B12)

A group of separate vitamins, not one single thing, mostly involved in converting food into usable energy and supporting nerve function. Found across whole grains, meat, eggs, and leafy greens — vitamin B12 specifically is found almost exclusively in animal products, which is why it is a common consideration for vegans.

Vitamin C

An antioxidant involved in immune function and collagen production, which supports skin, blood vessels, and wound healing. Found in citrus fruits, bell peppers, and broccoli.

Vitamin D

Helps the body absorb calcium for bone health and supports immune function. The body produces it from sun exposure on skin, and it is also found in fatty fish and fortified foods like milk.

Vitamin E

An antioxidant that helps protect cell membranes from damage. Found in nuts, seeds, and vegetable oils.

Vitamin K

Necessary for normal blood clotting and plays a role in bone metabolism. Found mainly in leafy green vegetables like kale and spinach.

Fat-soluble vs. water-soluble vitamins

Vitamins A, D, E, and K are fat-soluble, meaning the body stores them in fat tissue and the liver, so they do not need to be replenished daily and can build up if oversupplemented. Vitamins B and C are water-soluble, meaning the body does not store large reserves of them and excess amounts are typically flushed out through urine, which is why they need more regular replenishment through diet.

Diet covers most needs for most people

A varied diet supplies adequate amounts of most vitamins for most healthy people. Vitamin D and B12 are two commonly cited exceptions where deficiency is relatively common — worth discussing with a doctor rather than assuming, especially for people with limited sun exposure or plant-based diets.

Frequently Asked Questions

Can you get too much of a vitamin?

Yes, particularly with fat-soluble vitamins (A, D, E, K), since the body stores rather than excretes the excess. This is one of the reasons high-dose supplementation should generally be discussed with a doctor rather than done casually.

Do I need supplements if I eat a balanced diet?

Most people who eat a varied diet get sufficient amounts of most vitamins from food alone. Specific situations — certain diets, life stages, or medical conditions — can change that, so a doctor or dietitian is a better source for personalized advice than a general assumption either way.