What Are Vitamins?
Quick answer
Vitamins are organic compounds needed in small amounts for normal body functions. They do not provide calories, and each vitamin has distinct roles, food sources and deficiency risks.
- Understand fat- and water-soluble vitamins
- See why supplements are not interchangeable with food
- Recognize when individual advice may be needed
Two broad groups
Vitamins A, D, E and K are fat-soluble. The B vitamins and vitamin C are water-soluble. This affects absorption, storage and the consequences of excessive intake.
Small amount, important role
Vitamins participate in vision, blood formation, energy metabolism, immunity, bone health and many other processes.
Supplements require context
A supplement can help correct a deficiency or meet a specific need, but high doses can be ineffective, interact with medication or cause harm.
Vitamin C in an orange is accompanied by water, fibre and many food compounds. A tablet may provide vitamin C, but it does not reproduce the whole food.
Key terms
| Vitamin | An organic micronutrient required in small amounts. |
|---|---|
| Deficiency | Inadequate status that impairs normal function. |
| Fat-soluble | Absorbed with fat and stored to varying degrees. |
| Water-soluble | Dissolves in water and is generally less extensively stored. |
Common mistakes
- Judging a food by one nutrient while ignoring the whole food and overall eating pattern.
- Turning general public-health guidance into an exact personal prescription.
- Assuming a confident headline is stronger than the evidence behind it.
Practical takeaway
Use this lesson as a framework, not a rulebook. Look at foods in context, favour patterns you can maintain, and seek individual guidance when health conditions, medication, pregnancy, growth or significant dietary restriction change the situation.
Sources and further reading
- NIH Office of Dietary Supplements — Fact sheets
- World Health Organization — Healthy diet
- Health Canada — Healthy eating recommendations
Editorial note: NutritionLessons.com summarizes established guidance in plain language. Content is independently prepared from the sources shown and is not individually reviewed by a physician or dietitian. This page provides general education and does not diagnose, treat or replace individualized advice.