Niacin: How Much Do You Need?

Niacin: How Much Do You Need?

Niacin, or vitamin B3, is a water soluble vitamin that serves a number of purposes in your body. It supports your digestive function and nervous system, and your body needs niacin to metabolism energy from nutrients and cells. Niacin deficiency can lead to the serious disease pellagra, but too much niacin causes niacin toxicity, which can also be dangerous. Here are the facts about niacin and how much you need.

Niacin's Function in Your Body

Niacin is a water-soluble vitamin. That means it won't stay in your body, but will be excreted in your urine. Over time, it's possible to excrete all of the niacin in your body, so it's important to get enough niacin in your daily diet. Eating foods rich in tryptophan can help you get niacin, since your body can make niacin out of tryptophan.

Niacin supports a number of important body functions. Niacin helps your body metabolize energy stored in cells and it helps your body get the energy out of fats, protein and carbohydrates. Niacin supports skin health and both your brain and digestive tract need niacin to function. Niacin is considered one of the essential human nutrients.

Niacin is also good for your heart. It reduces levels of triglycerides and "bad" LDL cholesterol in your blood, while increasing levels of "good" HDL cholesterol. For this reason, niacin supplements are used to treat those with high blood cholesterol.

Consequences of Niacin Deficiency and Toxicity

Niacin deficiency, or lack of adequate niacin in the body and diet, causes serious physical symptoms and can even lead to death. However, niacin toxicity, or having too much niacin in the body or diet, can also cause serious health problems.

Niacin deficiency causes a condition known as pellagra. Symptoms of pellagra include:

  • Diarrhea
  • Dermatitis
  • Dementia
  • Lesions encircling the lower neck
  • Amnesia
  • Delirium
  • Irritability
  • Reduced metabolism
  • Anxiety
  • Depression
  • Death

Niacin toxicity can result in a number of symptoms, some more severe than others. If you're taking high dose niacin supplements for medical reasons, you may experience a side effect known as flushing. Your skin may flush for 15 to 30 minutes, and you may experience itching and tingling, particularly under your clothes. Taking niacin with meals or taking slow release supplements can ease this side effect; otherwise you'll adjust to the high doses of niacin in time and will no longer experience flushing symptoms.

Excessive use of niacin supplements without medical supervision can lead to severe consequences. Niacin toxicity can cause liver damage and failure, high blood sugar and gout.

Getting the Right Amount of Niacin

Your body won't experience any toxicity symptoms from niacin that it makes itself, using the amino acid tryptophan, but you should be careful with niacin supplements. Children should take between two and twelve mg per day. Adult women need no less than 14, but no more than 35 mg of niacin each day, unless they are pregnant or nursing, in which case they should take at least 18 mg per day. Men need between 16 and 35 mg per day.