Thiamin & Niacin

Flashcards reviewing thiamin and niacin, their sources, functions, deficiencies, and recommended dietary allowances.

Thiamin diphosphate (TDP)

Also known as thiamin pyrophosphate (TPP), it is the main coenzyme form of thiamin in the body.

Recommended Dietary Allowance (RDA) for Thiamin

For ages 14 and older: Males: 1.2 mg, Females: 1.1 mg; during pregnancy and lactation: 1.4 mg.

Sources of Thiamin

Includes meats (especially pork), legumes, nuts and seeds, whole grains, and enriched or fortified products.

Anti-thiamin factors

Substances like thiaminases and polyhydroxyphenols that inhibit thiamin absorption.

Thiamin Transporters (ThTr1 & ThTr2)

Proteins that mediate the uptake of thiamin into tissues from the blood.

Thiamin deficiency

Related to poor intake, absorption, increased loss, or utilization, particularly in at-risk populations.

Niacin

A generic term for nicotinic acid and nicotinamide, important for various biochemical roles.

Nicotinamide adenine dinucleotide (NAD)

A coenzyme found in its oxidized form (NAD+) and reduced form (NADH), essential for many metabolic reactions.

Tryptophan to Niacin conversion

1 mg of niacin can be produced from 60 mg of dietary tryptophan.

Niacin toxicity

Associated with pharmacological doses of nicotinic acid, side effects may occur at doses greater than 1 g/day.

Coenzyme roles of Niacin

Involves energy production, nutrient metabolism, and redox reactions.

Nonredox roles of Niacin

Involves DNA repair, cell regulation, and apoptosis through ADP-ribosylation reactions.

NAD+ boosting lifestyle strategies

Include 8 hour feeding cycles, calorie restriction, exercise, and exposure to heat/cold.

Niacin deficiency causes

Inadequate oral intake, poor bioavailability, metabolic disorders, and chronic alcoholism.