Complete Info on Vitamin B3 aka Niacin: Functions, RDA, Deficiency & More

What Is Vitamin B3 Aka Niacin?

Vitamin B3, also known as niacin, is one of the B-complex vitamins essential for various physiological functions in the body. It is a water-soluble vitamin, meaning it is not stored in the body and must be obtained regularly through the diet. Niacin can be found in food and supplements in two different forms: nicotinic acid and nicotinamide. Tryptophan, an amino acid, can also be transformed by the body into nicotinamide. (Source)

What Are The Functions Of Vitamin B3 Aka Niacin?

Niacin plays several crucial roles, including:

1. Energy Metabolism: Niacin is involved in the conversion of carbohydrates, fats, and proteins into energy that the body can use for various functions.
2. Cell Signaling: It plays a role in cell communication and is essential for the proper functioning of enzymes that are involved in numerous metabolic processes.
3. Healthy Skin: Niacin can help maintain healthy skin by supporting the repair of damaged skin cells.
4. Digestive System Health: It contributes to the proper functioning of the digestive system, as niacin is needed for the synthesis of enzymes that aid in digestion.
5. Nervous System Function: Niacin is important for maintaining the health of the nervous system and is involved in the production of certain neurotransmitters.
6. Cardiovascular Health: Niacin has been used to manage cholesterol levels, as it can help raise high-density lipoprotein (HDL or “good”) cholesterol and lower low-density lipoprotein (LDL or “bad”) cholesterol.
7. Blood Sugar Regulation: Some studies suggest that niacin may help regulate blood sugar levels.

How Much Vitamin B3 Do I Need? What Are The Recommended Amounts?

RDA:  Niacin is measured in milligrams (mg) of niacin equivalents (NE). To calculate niacin equivalents, 1 NE is equivalent to either 60 mg of tryptophan or 1 mg of niacin. For individuals aged 19 and older, the Recommended Dietary Allowance (RDA) is as follows: 14 mg NE for women, 18 mg NE for pregnant women, 17 mg NE for lactating women, and 16 mg NE for men.

UL:  The daily intake amount that is least likely to have a negative impact on health is known as the Tolerable Upper Intake Level. Niacin’s UL for all adults aged 19 and over is 35 milligrams.

What Happens If There Is Excess Of B3 Aka Niacin?

Excessive intake of vitamin B3, also known as niacin, can lead to a condition known as niacin toxicity or niacin overdose. Niacin is a water-soluble vitamin, which means that excess niacin is typically excreted from the body through urine. However, excessive intake of niacin, particularly from supplements or fortified foods, can lead to various side effects, including:

1. Skin Flushing
2. Digestive Upset
3. Liver Damage
4. Gout
5. Glucose Intolerance
6. Elevated Blood Sugar Levels

It’s important to emphasize that these side effects are generally associated with very high doses of niacin, often exceeding what is typically found in standard supplements or through a balanced diet. For most individuals, niacin is well-tolerated and safe when used within recommended dietary guidelines.

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What Are The Food Sources?

Nicotinic acid and nicotinamide are the two different types of niacin. Food contains both of them.

Good sources of niacin include (Source):

• Meat
• Fish
• Wheat flour
• Eggs
• Pumpkin Seeds
• Lentils
• Yogurt
• Bulgur
• Banana

Deficiency: The possible disorders And Their Symptoms

In the United States and other industrialized nations, niacin deficiency is uncommon because it is added to many foods and multivitamins, is well-absorbed from the majority of foods, with the exception of some cereal grains where niacin is bonded to its fibers and reduces absorption.

A severe niacin deficiency results in pellagra, a disorder that causes constipation/diarrhea, a bright red tongue, and a black, occasionally scaly rash to appear on skin areas exposed to sunlight. A significant niacin deficit can also manifest as:

• Depression
• Headache
• Fatigue
• Memory loss
• Hallucinations

Groups At Risk For Deficiency

• Limited Diets. People whose diets are limited in both variety and quantity of foods, such as those living in poverty or who are very ill and cannot eat a balanced diet, are at increased risk. Developing countries that eat corn or maize as the main food source are at risk for pellagra, as these foods are low in both absorbable niacin and tryptophan.
• Chronic Alcoholism. With excessive alcohol use, the absorption of various nutrients is reduced, especially water-soluble vitamins like those in the B family. (Source)
• Carcinoid Syndrome. This condition affects cancer cells in the intestines that are slow-growing and emit the neurotransmitter serotonin. The syndrome raises the risk of low niacin by causing tryptophan in the food to be converted into serotonin rather than niacin.

Toxicity Of Vitamin B3 Aka Niacin In case Of Excess Of Of Vitamin B3 Aka Niacin

Niacin-containing foods seldom cause toxicity, however, supplements taken at high doses over an extended period of time can. On the face, arms, and chest, there may be a crimson skin flush and irritation or tingling. Flushing generally happens when high-dose supplements in the form of nicotinic acid are used, as opposed to nicotinamide.

Other symptoms:

• Dizziness
• Low blood pressure
• Fatigue
• Headache
• Upset stomach
• Nausea
• Blurred vision

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