What are vitamins?

The word says it all: “vitamin” comes from the Latin vita, life. They are substances we need in tiny amounts, yet without which the body simply doesn’t work properly. The curious part is that, with a few exceptions, we can’t make them ourselves: we have to get them from food.

What they are (and what they aren’t)

Vitamins are organic compounds essential for growth, development, and the normal functioning of cells. Unlike carbohydrates, fats, or proteins, they provide no energy (they have no usable calories as fuel), but they act as key players in hundreds of reactions in the body. As Harvard’s Nutrition Source explains, vitamins perform vital roles in metabolism even though the body only needs them in small doses.

Among other things, vitamins help to:

• Release energy from food.
• Keep the skin and nervous system healthy.
• Produce red blood cells.
• Strengthen the immune system and bone formation.

The 13 essential vitamins

According to MedlinePlus, there are 13 essential vitamins: A, C, D, E, K, and the eight B vitamins (B1, B2, B3, B5, B6, B7, B9, and B12). “Essential” means the body needs them to function and that, for the most part, we must obtain them through diet.

Two big groups: water-soluble and fat-soluble

This is the key distinction for understanding them, as the Oklahoma State University Extension describes:

1. Water-soluble (dissolve in water): all the B vitamins and vitamin C. The body does not store them in large amounts, so the excess is flushed out in urine and they should be replenished regularly.
2. Fat-soluble (dissolve in fat): vitamins A, D, E, and K. These are stored in the liver and fatty tissue as a reserve… but they can also reach toxic levels if taken in excess.

Where to get them

For most people, a varied diet covers vitamin needs:

• Fruits and vegetables (vitamin C, folate, beta-carotene).
• Fish, eggs, and dairy (vitamins D, B12, A).
• Whole grains and legumes (B-complex).
• Nuts and vegetable oils (vitamin E).
• Moderate sun exposure helps produce vitamin D.

What about supplements?

Here it’s worth debunking a common myth: “the more vitamins, the better.” Not so. In healthy people who eat well, taking megadoses offers no extra benefit and, in the case of fat-soluble vitamins, the excess can be harmful. Supplementation makes sense in specific situations —pregnancy, certain restrictive diets, malabsorption, or diagnosed deficiencies— but it’s always best to check with a health professional before turning to it.

Small doses, big importance

Vitamins are the perfect example that what’s essential isn’t always what’s abundant: tiny amounts are enough, yet their absence causes disease and their excess can do harm. The best strategy isn’t to stockpile pills, but to eat a variety of foods. With a colorful, balanced plate, your body usually has everything it needs for those thirteen little “sparks of life” to do their job.