GLOSSARY

Niacin Equivalents (NE) combine dietary niacin activity with convertible tryptophan contribution rather than directly adding all precursor weights.

Niacin equivalents include preformed niacin and synthesis from tryptophan. The common convention counts about 60 milligrams dietary tryptophan as 1 milligram niacin, a planning average rather than an identical conversion in everyone. Total protein grams are not pure tryptophan, and this ratio cannot directly determine a personal amino-acid supplement dose or replace an adequate diet.

Niacin includes nicotinic acid, nicotinamide and related compounds used to make NAD and NADP. These carriers participate in redox reactions and cellular functions. Oxidised NAD and its reduced form are chemically distinct. A related name on a supplement does not guarantee intact delivery into muscle or better performance; absorption and cellular regulation still intervene.

Meat, fish, peanuts and enriched grains contribute niacin, while protein also supplies tryptophan. Severe deficiency can cause pellagra, but flushing from nicotinic acid is not evidence of better energy production. High doses can cause adverse effects and interactions. Nicotinamide and nicotinic acid are not fully interchangeable in pharmacological effects or tolerability, despite sharing a vitamin family.

In a high-protein diet analysis, use a consistent basis for table niacin and tryptophan contribution to avoid double counting.

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.

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.