Vitamin B-3

Functions

• enhances nerve function, appetite, and digestion
• component of two important enzymes
• important in glycolysis, tissue respiration, and fat synthesis
• used in production of sex and stress hormones
• improves circulation
• reduces risk of non-melanoma skin cancers by repairing damaged DNA

Deficiency

Mild

• Digestive
  • diarrhea
  • gastrointestinal disturbances
  • vomiting
• Psychological
  • mental disturbances
  • depression
  • headache
  • apathy
  • fatigue
  • disorientation and dizziness
  • memory loss
  • insomnia
  • loss of appetite
• canker sores
• thick, scaly pigmented rash on skin exposed to sunlight
• swollen mouth and bright red tongue

Severe

• pellagra
• death, if not treated

Characteristics

• soluble in hot water and alcohol
• not destroyed by heat, light, air, or alkali
• not destroyed in ordinary cooking

Good Sources

Natural

• lean meat
• liver
• fish
• legumes and peanuts
• nuts
• whole-grains
• potatoes

Artificial

• yeast
• enriched foods

Recommended Daily Allowances (RDA)

• Males (11 yrs. and older)
  • 16 mg
  • 16-19 mg
• Females (11 yrs. and older)
  • 14 mg
  • 13-15 mg
• Pregnant females
  • 17 mg
• Lactating females
  • 20 mg
• Children
  • 9-16 mg
• Infants
  • 6-8 mg
• Varied values reflect different references

Tolerable Upper Intake Levels (UL)

• Adults (19 to 50 yrs)
  • 35 mg
• Intakes above UL may lead to negative health consequences.
  • Mild: Nausea, vomiting, abdominal cramps, diarrhea, flushing
  • Severe: Liver damage, irregular heart rate, large rashes, gouty arthritis

Supplementation

• 25-300 mg commonly recommended
• Best taken with vitamin B complex and vitamin C
• Large doses may be prescribed by doctor to lower blood cholesterol.
• May cause flushing and gastrointestinal distress.
  • Nicotinic acid, but not nicotinamide causes vasodilation and flushing