Summary
Organic micronutrients needed in small amounts, often serving as coenzymes in metabolic reactions.
In depth
Water-soluble vitamins (B group, C) are not stored well and are excreted in urine; fat-soluble ones (A, D, E, K) can accumulate. Many B vitamins are the precursors of coenzymes such as NAD (niacin) and FAD (riboflavin).
Deficiency diseases include scurvy (vitamin C, needed for collagen), rickets (vitamin D and calcium) and beriberi (thiamine).
Humans cannot make most vitamins, so deficiency produces specific disease: vitamin C (scurvy), D (rickets), A (night blindness), B1 (beriberi), B3 (pellagra), B12 (pernicious anaemia) and K (bleeding). Folate before and during early pregnancy reduces neural tube defects, so many cereals are fortified.
Vitamin D is made in skin from cholesterol derivatives under UV light, and it controls calcium absorption; vitamin K is needed to make clotting factors, and some of it is made by gut bacteria. Antioxidants such as C and E neutralise reactive oxygen species.
Example: sailors in the 18th century were cured of scurvy by citrus fruit, one of the first controlled trials, by James Lind in 1747.
Frequently asked questions
What is Vitamins?
Organic micronutrients needed in small amounts, often serving as coenzymes in metabolic reactions.
Which area of biology covers Vitamins, and how advanced is it?
Vitamins is one of the 51 topics in Biomolecules & Biochemistry. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Cofactors and Coenzymes, Minerals in Biology, Lipids.
Can you give an example of Vitamins?
Vitamin K helps form clotting factors, so newborns may be given a dose.
What should I learn before Vitamins?
Vitamins is a Beginner topic, so no earlier topic is required. Other Beginner topics in Biomolecules & Biochemistry that pair well with it include Water Properties, Carbon Chemistry, Carbohydrates.
What topics are related to Vitamins?
The closest topics to Vitamins are Cofactors and Coenzymes, Minerals in Biology, Lipids, Ribozymes. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Vitamins?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Vitamins. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
How is Vitamins different from Cofactors and Coenzymes?
Vitamins: Organic micronutrients needed in small amounts, often serving as coenzymes in metabolic reactions. Cofactors and Coenzymes: Non-protein helpers such as metal ions or vitamin-derived molecules that many enzymes require to function. Read both side by side and note what each one explains.
How should I study Vitamins step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Cofactors and Coenzymes and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.