Vitamin B3 (Niacin, Niacinamide) | Deficiencies, Excesses and Recommendations

Vitamin B3 (Niacin, Niacinamide) | Deficiencies, Excesses and Recommendations

Niacin is responsible for converting food into useable energy, and is recruited to help with DNA production and repair. Nearly every multivitamin contains vitamin b-3 as either niacin or niacinamide. Some include both forms.

Vitamin B-3 is the name for a collection of compounds that the body needs to produce NAD. NAD is used in over 450 reactions by the human body. This is more than any other vitamin-derived molecule.

The only two forms of B-3 discussed in this article are niacin and niacinamide. Although either of these can prevent diseases of vitamin b-3 deficiency, each have their own unique functions in the body as well.

What Could Happen If You Don’t Get Enough B-3?

Please note that niacin deficiency is extremely rare in present day developed countries.

  • Fatigue
  • Depression
  • Possible increased cancer risk
  • Possible birth defects in the children of mothers with niacin deficiency
  • Pellagra. This is the result of a severe deficiency and produces mental symptoms similar to schizophrenia. It also affects the skin, digestive system, and can be lethal.R*

B-3 deficiency may not always be the result of inadequate intake of niacin. It can also be the result of other things that affect its absorption or utilization, such as:

  • Alcohol Use Disorder (alcoholism)

What Could Happen If You Get Too Much B-3?


  • Liver damage
  • High blood sugar
  • Gout-like symptoms
  • Gastrointestinal issues
  • Extreme flushing and itching
  • Long term use of high amounts may increase risk of diabetes
  • Possible birth defects in children of mothers who take too much niacin

A common side effect of even safe amounts of niacin is flushing and itching. Although alarming, a “niacin flush” will usually go away in a few hours without any other intervention.


  • Liver damage
  • Gastrointestinal issues

Niacinamide does not cause flushing and itching like niacin.

Little Changes to Your Diet to Get More

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Incorporate plenty of poultry and fish (e.g. salmon, tuna) into your diet, or the plant sources of portobello mushrooms, potatoes, and fortified cereals.

If you choose to take a supplement, we generally recommend using a brand that submits to independent, third-party testing, or has been independently tested and approved by Consumer Labs.

Niacin 100mg
Niacin 100mg
Necessary for normal metabolism of fats and energy release from carbohydrates.
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Now Foods Niacinamide 500mg
Now Foods Niacinamide 500mg
Niacinamide (Vitamin B-3) is a form of Niacin, a water soluble B-Vitamin. It is a derivative of Niacin that does not cause the "flush" normally associated with taking high doses of Niacin.
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Potential Life Enhancements

  • Skin. Topical niacinamide gel has been used to decrease the severity of acne. R. Due to niacinamide’s role in DNA repair, some use niacinamide topically, or internally to speed up sunburn recovery and reduce its damaging effects on the skin.
  • Cardiovascular. Prescription niacin products are used for people to support healthy blood cholesterol levels. The high dose of niacin needed to improve blood markers for heart health should be used under medical supervision.
  • Emotional health. Some people use niacinamide as a natural way to stay calm. Niacinamide appears to have properties in common with benzodiazepines, and has demonstrated anti-anxiety effects, such as muscle relaxation in animals. R There are a few case reports of physicians using both niacin and niacinamide to speed up benzodiazepine withdrawal for their patents. R Obviously, you shouldn’t try this one on your own.

Vitamin Lore

This section contains a quick fact check regarding some myths that have circulated about niacin.

  • The Niacin Flush. The immediate histamine release from taking about 50mg or more of niacin causes the niacin flush. This is a temporary reddening and itching of the skin often accompanied by hot flashes. This is very real, and also benign. On the other hand, some products include niacin in their formulations, and then use marketing language to explain the niacin flush by claiming that “you can feel it working” or that you can feel your body “detoxing.” This is false.
  • Drug Tests. Some claim that large doses of niacin will help pass urine tests for recreational drugs. This has been disproven, but it’s important to note that attempts to pass drug tests using high does of niacin have lead to multiple organ failure. R.
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