B3 Niacin Flashcards
Where is niacin absorbed in the body?
Stomach and mostly in the small intestine
What is the conversion ratio of tryptophan to niacin?
60mg of tryptophan = 1mg Niacin
What are the Recommended Dietary Intakes (RDI) of niacin for males and females?
16mg/day for males and 14mg/day for females; 18mg/day in pregnancy
What are therapeutic doses of niacin?
10 - 500mg/day in the form of nicotinamide
What are the two forms of niacin?
- Nicotinic acid
- Niacinamide
What is the maximum allowable amount of nicotinic acid in supplements?
Up to 100mg
Where is niacin stored in the body?
- Liver
- Heart
- Kidneys
- Muscles
What is a primary function of niacin?
Energy production and metabolism of many compounds
What role does niacin play in cell replication?
Cofactor for enzymes to make and repair DNA
What are some antioxidants that niacin supports?
- Vitamin C
- Glutathione
- Thioredoxin regeneration
Which amino acids does niacin support transamination for?
- Glutamate to GABA
- L-dopa to dopamine
- Tryptophan to niacin
What effect does niacin have on HDL cholesterol?
Potential to increase HDL and greater excretion of overall cholesterol
What is Pellagra?
Deficiency of niacin characterized by dermatitis, diarrhoea, dementia, and death
What are some sources of niacin?
- Liver
- Meat
- Coffee
- Tea
- Fortified breads and cereals
- Vegemite
What factors increase the demand for niacin?
- High intake of corn and refined grains
- Low protein/undernutrition
- Low intake of B2, B6, and iron
- Increased coffee, tea, soft drinks, and chocolate
- Drugs and medications
- Alcohol
- Disorders of GI tract
What are signs and symptoms of niacin deficiency?
- Pellagra
- Dermatitis
- Diarrhoea
- Dementia
- Gi tract malabsorption
- Decreased HCL
- Gastritis
- Sore inflamed tongue
- Tremors
- Fatigue
- Irritability
- Nausea
- Anorexia
- Insomnia
- Dizziness
- Noise and light sensitivity
- Headaches
- Microcytic anaemia
What are the potential effects of severe niacin deficiency?
Can cause dementia, depression, or Alzheimer’s
What is a common toxicity symptom of high doses of nicotinic acid?
Niacin flush
What are some symptoms of niacin toxicity?
- Nausea
- Vomiting
- Liver toxicity
- Increased BSL
- Mild insulin resistance
- Headaches
- Dizziness
- Nerve damage
- Skin lesions
