Vitamin B3
In this post, we will cover yet another important water-soluble vitamin -Vitamin B3 also known as niacin. Vitamin B3 is contained mainly in 2 forms including nicotinamide and nicotinic acid.Tryptophan (an amino acid) can be converted into Vitamin B3 -nicotinamide .
Functions Of Vitamin B3
Vitamin B3 functions in the body as a coenzyme. It is involved in numerous reactions ,and approximately 400 enzymes require it during these reactions.
- Its coenzymes are involved in oxidation–reduction reactions– The coenzymes (NAD+ and NADP+) participate in the electron transport of several enzymes involved in tissue respiration, lipid metabolism, and glycogenolysis(glycogen is broken down to glucose).
- Used in the production of cholesterol and fats –Vitamin B3 not only enhances the circulation of cholesterol levels but also maintains its levels.
- Supports the repair of genetic material -It is involved in the production and repair of DNA.
Sources Of Vitamin B3
- Fish-salmon, mackerel, sardines, trout, tuna
- Lean meats- beef, pork, poultry
- Organ meats –beef liver
- Eggs
- Whole grains-brown rice, barley, wheat
- Seeds- pumpkin seeds, sunflower seeds
- Nuts -ground nuts
- Legumes – beans, peas, lentils
- Maize
- Potatoes
- Broccoli
- Pepper
- Mushrooms
RDA
- Males 19 years and above-16 milligrams
- Females 19 years and above-14 milligrams
- Expectant women -18 milligrams
- Lactating women- 17 milligrams
Individuals At Risk Of Vitamin B3
- Individuals who consume diets low in tryptophan –Inadequate consumption of other vitamins and minerals including Vitamin B2, B6, and iron, which are significant in the conversion of tryptophan into niacin, can contribute to its deficiency.
- Individuals with certain conditions-Carcinoid syndrome and Hartnup disease decrease the body’s capacity to convert tryptophan to niacin.
Vitamin B3 Deficiency
Deficiency results in a condition known as Pellagra, which is characterized by 3 main symptoms namely: dermatitis, dementia, and diarrhea.In severe cases, pellagra can be fatal.
Other symptoms include:
- A pigmented rash on skin after sun exposure
- Red tongue
- Fatigue
- Headaches
- Vomiting
- Constipation
- Flaky skin
- Oral ulcers
- Memory loss
- In severe cases, hallucinations
Compared to other water-soluble vitamins such as Vitamin B1, vitamin B3 is not easily destroyed by cooking ;nonetheless, it is less bio-available in some of its sources, especially maize. In addition, apart from poor diets, Vitamin B3 deficiency can result from malabsorptive conditions, interactions with certain medicines, and genetic disorders.
Vitamin B3 Toxicity
There is not an established toxicity level for Vitamin B3. Toxicity resultant from the consumption of foods containing niacin is rare, although it can occur from long-term usage of supplements. Common signs and symptoms of toxicity include: the reddening of the skin accompanied with itchiness on the chest, arms and face .
Nutrient Interactions With Vitamin B3
Vitamin B3 (niacin), Zinc, and Vitamin B2 work together to promote the conversion of vitamin B6 (pyridoxine) into its functional form for utlization in the body.
Drug Interactions With Vitamin B3
Isoniazid : Isoniazid (medicine used in the treatment of tuberculosis), may cause Vitamin B3 deficiency.
These medicines may also decrease the levels of Vitamin B3 in the body:
- Azathioprine (Imuran)
- Levodopa and carbidopa
- Chloramphenicol (Chloromycetin)
- Fluorouracil
- Cycloserine (Seromycin)
- Mercaptopurine (Purinethol)