GLOSSARY

Vitamin Requirement is the amount needed for suitable function and status, distinct from actual intake or a tolerable upper limit.

Vitamin needs vary with age, life stage and circumstances; a population reference is not a personalised prescription. More training does not automatically multiply the need for every vitamin. Eating more to meet energy demand often also increases vitamin intake. Food quality and actual restrictions should therefore be assessed before assuming a supplement is necessary.

Intake, absorption and body status describe different stages. An apparently adequate recorded intake may coexist with malabsorption, illness or drug interactions. Conversely, one low-intake day does not establish clinical deficiency. Several days of intake, relevant history and an appropriate marker provide more information than one meal or nonspecific tiredness alone.

An adult product dose does not determine an adolescent athlete's requirement; age and actual diet matter.

A varied food pattern is more useful than reliance on one food or capsule. Fruit, vegetables, grains, pulses, dairy or fortified alternatives and protein foods make different contributions. Long-term exclusions, very low energy intake, travel and restricted access can create gaps in sports diets; food records help identify which sources are actually missing.