At a glance......
What Food is High in Niacin/Niacin is a water-soluble vitamin belonging to the vitamin B family, which occurs in many animal and plant tissues, with antihyperlipidemic activity. Niacin is converted to its active form niacinamide, which is a component of the coenzymes nicotinamide adenine dinucleotide (NAD) and its phosphate form, NADP. These coenzymes play an important role in tissue respiration and in glycogen, lipid, amino acid, protein, and purine metabolism. Although the exact mechanism of action by which niacin lowers cholesterol is not fully understood, it may act by inhibiting the synthesis of very-low-density lipoproteins (VLDL), inhibiting the release of free fatty acids from adipose tissue, increasing lipoprotein lipase activity, and reducing the hepatic synthesis of VLDL-C and LDL-C.
Niacinamide is the active form of vitamin B3 and a component of the coenzyme nicotinamide adenine dinucleotide (NAD). Niacinamide acts as a chemo- and radio-sensitizing agent by enhancing tumor blood flow, thereby reducing tumor hypoxia. This agent also inhibits poly(ADP-ribose) polymerases, enzymes involved in the rejoining of DNA strand breaks induced by radiation or chemotherapy.
Vitamin B3 also referred to as niacin, is the generic term for nicotinic acid, its amide (nicotinamide or niacinamide), and their biologically active derivatives. It is also found in the form of the pyridine nucleotide coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADPH). These are essential in all cells for energy production, metabolism, and DNA repair. Severe deficiency results in pellagra, which is a combined deficiency of both niacin and its precursor, tryptophan. The symptoms of deficiency are primarily dermatitis, diarrhea, and dementia. Death results if the condition is untreated.
Deficiency Symptoms of Vitamin B3 / Niacin
- Severe niacin deficiency leads to pellagra, a disease characterized by a pigmented rash or brown discoloration on skin exposed to sunlight; the skin also develops a roughened, sunburned-like appearance [rx,rx,rx,rx].
- Pellagra is uncommon in industrialized populations and is mostly limited to people living in poverty, such as refugees and displaced people who eat very limited diets low in niacin and protein [rx,rx]. Pellagra was not uncommon in the early 20th century among individuals living in poverty in the southern United States and parts of Europe whose limited diets consisted mainly of corn [rx,rx].
- Symmetrical lesions on both sides of the body. The lesions are most visible at pressure points and on areas of the skin exposed to the sun. Some people develop lesions that cover their entire hands or feet.
- Butterfly-shaped lesions on the face, or a “necklace” of lesions around the neck that develops after spending time in the sun.
- Pain, swelling, and irritation of the mouth or other mucous membranes, such as the vagina or the urethra. Severe deficiency can cause the tongue to turn red or swell. Some people develop sores under the tongue or on their lips.
- Pain and burning in the throat, chest, or stomach.
- Digestive pain, such as swelling, vomiting, nausea, diarrhea, and constipation. Some people develop ulcers in their bowels that cause bloody diarrhea.
- Changes in personality and mental health, including losing contact with reality (psychosis), confusion, memory problems, depression, and paranoia. Sometimes, these symptoms may be incorrectly diagnosed as mental illness.
- irritated or red skin
- unexplained digestive problems
- mood issues, such as anxiety or depression
- changes in thinking or the ability to concentrate
- poor circulation
Food Source of Vitamin B3 / Niacin
Niacin is found in a variety of whole and processed foods, including fortified packaged foods, meat from various animal sources, kinds of seafood, and spices.
Among whole food sources with the highest niacin content per 100 grams
- cooked skipjack tuna, 18.8 mg
- cooked light meat turkey, 11.8 mg
- cooked, lean ground pork, 11.1 mg
- cooked venison, 10.8 mg
- cooked, lean veal, 8.0 mg
Plant foods and spices
- sesame seed flour, 12.5 mg
- ground ginger, 9.6 mg
- dried tarragon, 9.0 mg
- dried, green sweet peppers, 7.4 mg
- grilled portobello mushrooms, 6.2 mg
- roasted sunflower seeds, 4.1 mg
- dehydrated apricots, 3.6 mg
- baked potato, 3.1 mg
The U.S. Department of Agriculture’s (USDA’s) FoodData Central lists the nutrient content of many foods and provides a comprehensive list of foods containing niacin arranged by nutrient content and by food name.
Fortified breakfast cereals have among the highest niacin contents (more than 20 mg per 100 grams). Whole grain flours, such as from wheat, rice, barley or corn, and pasta have niacin contents in a range of 3–10 mg per 100 grams.
Daily Requirement of Vitamin B3 / Niacin
Intake recommendations for niacin and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by an expert committee of the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine [rx]. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and sex, include:
- Recommended Dietary Allowance (RDA) – Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals.
- Adequate Intake (AI) – Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA.
- Estimated Average Requirement (EAR) – Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals.
- Tolerable Upper Intake Level (UL) – Maximum daily intake unlikely to cause adverse health effects.
Table 1 lists the current RDAs for niacin as mg of niacin equivalents (NE) [rx]. The FNB defines 1 NE as 1 mg niacin or 60 mg of the amino acid tryptophan (which the body can convert to niacin).
Intake recommendations for vitamin B3 or niacin and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and sex, include:
Health Benefit of Vitamin B3 / Niacin
Vitamin B3 (niacin) is important for the body because it helps to:
- Niacinamide is the active form of vitamin B3 and a component of the coenzyme nicotinamide adenine dinucleotide (NAD). Niacinamide acts as a chemo- and radio-sensitizing agent by enhancing tumor blood flow, thereby reducing tumor hypoxia. This agent also inhibits poly(ADP-ribose) polymerases, enzymes involved in the rejoining of DNA strand breaks induced by radiation or chemotherapy.
- Niacin is prescribed pharmacologically to lower LDL fats and triglycerides by preventing the breakdown of fats into these individual components. Niacin consumed at such high levels can cause rashes, headaches, nausea, and diarrhea. Consult your doctor before taking niacin supplements in high doses.
- Studies suggest that vitamin B3 (niacin) can help decrease insulin sensitivity, however, other studies find no difference. Niacin has also been shown to help alleviate some of the destructive autoimmune reactions of type I diabetes, and further studies are being conducted to asses its effectiveness.5
- Studies show that niacin reduces cancer risk via ensuring DNA integrity and maintenance, and through proper regulation of the tumor suppressor gene: p53.
- An observational study has reported slowing the progression of AIDS and increasing survival with high doses of niacin.
- The body’s immune system creates a specific cytokine, interferon-gamma, which breaks down tryptophan, a precursor of niacin. Studies show that HIV patients who take increased levels of niacin slow the progression of AIDS.
- Bran, which is high in vitamin b3, is typically removed during any refining process. Anyone who eats high amounts of white bread, white rice, corn syrup, or other refined products will not receive adequate amounts of niacin. Even though most of these foods are now fortified, it is still best to eat unrefined food products.
- Convert food into glucose, used to produce energy
- Produce macromolecules, including fatty acids and cholesterol
- Facilitate DNA repair and stress responses.
- Normal energy-yielding metabolism
- The normal function of the nervous system
- The maintenance of normal skin and mucous membranes
- Normal psychological functions
- The reduction of tiredness and fatigue.