Vitamins and minerals

Vitamins and minerals are micronutrients — substances required in small quantities that the body largely cannot make on its own and must obtain from food. Unlike carbohydrates, fats, and protein, micronutrients supply no calories; instead they enable the chemical reactions that release and use energy, build tissue, and keep organ systems functioning.

Vitamins are organic compounds classified by how they're absorbed and stored. The fat-soluble vitamins — A, D, E, and K — are absorbed with dietary fat and stored in the liver and fat tissue, which means excess intake can accumulate to toxic levels. Water-soluble vitamins — vitamin C and the B-complex vitamins — are generally not stored in appreciable amounts, so they must be consumed regularly and excesses are mostly excreted in urine; vitamin B12, which the liver stores for years, is the notable exception.

Minerals are inorganic elements. Major minerals such as calcium, phosphorus, magnesium, sodium, and potassium are needed in larger amounts and support bone structure, fluid balance, muscle contraction, and nerve conduction. Trace minerals — iron, zinc, iodine, selenium, and others — are needed in tiny amounts but are critical: iron carries oxygen in hemoglobin, and iodine is required for thyroid hormone. Many vitamins and minerals also act as coenzymes and cofactors in energy metabolism, and some, like vitamins C and E and selenium, serve antioxidant roles. Needs shift across life stages — calcium and vitamin D become especially important for older adults maintaining bone density.

Micronutrients appear across several certification exams. The CSCS tests vitamins and minerals within sports nutrition and their role in supporting training and older adult health, the CCMA covers them in nutrition and pharmacology basics, and the MBLEx touches on minerals in blood physiology.