Micronutrient Monday: Vitamin B3 (Niacin)

Role of Niacin in the Body 

Our bodies use vitamin B9 to turn food into energy, support our skin, immune system and digestive system. We also need niacin to help over 400 enzymes complete their reactions.  

How Much Do I Need?

Health Canada recommends healthy individuals over the age of 14 consume between 14 and 16 milligrams of niacin equivalents (NE) each day, while children between the ages of 9 and 13 should consume 12 milligrams of NE daily. The amount of niacin that our bodies need can vary depending on many factors including age, sex, lactation and pregnancy. You can visit Health Canada’s website for a complete list of recommended intakes. 

Our bodies can make small amounts of niacin from tryptophan, one of the building blocks of protein. Niacin equivalents accounts for both the niacin we consume, as well as the niacin that our bodies make.  

Am I At Risk of Deficiency?

Some groups of people have a higher risk of niacin deficiency than others. This includes, 

• • People experiencing undernutrition
  • People lacking other micronutrients in their diet – If we do not consume an adequate amount of other vitamins and minerals (such as riboflavin, vitamin B6 and iron), our bodies will sacrifice vitamin B9 to make some compounds. This means our bodies are using more vitamin B9 than normal.
  • People with Hartnup disease
  • People with carcinoid syndrome

If we don’t consume enough vitamin B9, our bodies can convert tryptophan (one of the building blocks of proteins) into niacin.   Although our bodies can make small amounts of niacin from tryptophan, we will still begin to show signs and symptoms after long periods of vitamin B9 deficiency. Some signs and symptoms include,  

• • Bright red tongue
  • Vomiting
  • Depression and other changes in mental health
  • Excessive tiredness
  • Hallucinations
  • Memory loss

Severe niacin deficiency can lead to pellagra.  

Can I Have Too Much Niacin?

Although niacin is a water-soluble vitamin, it is possible to have too much. Generally, we do not consume enough niacin in food to cause any negative side effects. However, dietary supplements can be dangerous and have a wide range of effects.  

The adverse effects of consuming too much vitamin B3 depend on which type of supplement you are taking. For example, nicotinamide supplements can cause diarrhea, vomiting and easily bruising, while nicotinic acid supplements can cause low blood pressure, high blood sugar, stomach pain and blurred vision. Consuming large amounts of nicotinic acid supplements for long periods can lead to hepatitis and liver failure. 

Like many other B vitamins, vitamin B9 is naturally found in many foods. It is also added to other foods to increase their nutritional value and ensure we are getting the vitamins and minerals that our bodies need. Some niacin-rich foods include,

• • Chicken breasts
  • Salmon
  • Pork tenderloin
  • Ground beef
  • Brown rice
  • Peanuts
  • Fortified breakfast cereal
  • Sunflower seeds
  • Pumpkin seeds
  • Soy milk

Dietary Supplements

Niacin is also found in many vitamin supplements including, individual supplements, B-complex supplements and multivitamins. 

Consuming too many dietary supplements can increase our side effects from toxicity or interactions with medications. You should always chat with your doctor or dietitian before starting new supplements to make sure they are the right fit for you. 

Interaction with Medications

Vitamin B9 supplements can interact with a few medications, leading to adverse side effects. Some medications the vitamin can interact with including,  

• • Medications used for the treatment of tuberculosis
  • Some diabetes medications

For more on the role of vitamins and minerals in promoting health and supporting our bodies, check out the Micronutrient Monday series.