Vitamin B3: Niacin Uses, Benefits, and Side Effects

Takeaway: Vitamin B3 niacin is a water-soluble B-complex vitamin that is responsible for converting macronutrients to energy and for managing various important bodily functions. It is popular for its heart-protecting properties. It is said to have the ability to lower cholesterol, reduce blood sugar levels, and may even be a cure for anxiety disorder.

Vitamin B3 Overview

As the name suggests, vitamin B3 – also known as niacin, is a member of the vitamin B-complex family. And as such, it is also a water-soluble vitamin that is essential for the body to maintain its optimal health.

Almost every part of the human body needs vitamin B3 to function normally. Vitamin B3 niacin takes part in various roles from the functions of the brain to the health of one’s skin. But, due to its water-soluble characteristics, this also means that the body does not naturally have storage for niacin as a backup.

When niacin is sparse, the body needs replenishment either through the consumption of niacin-rich foods or with the help of supplements. Most vitamin B3-filled food options come from animal protein.

Meats such as beef liver, chicken, and turkey are some of the best sources of niacin. There is also a good selection of fish such as tuna and salmon with that are rich in various vitamins and minerals like niacin. Meanwhile, vegan options include brown rice, avocados, mushrooms, tomatoes, green peas, and peanuts.

Tomatoes contain vitamin B3

Having said all that, it is apparent that food options for vegans may be limited, in comparison to animal-sourced vitamin B3. Moreover, the niacin content in meat is significantly higher than in vegetables. Four ounces of lean ground beef yields 12% of the daily value of niacin while two cups of raw spinach only have 2% of its daily value. Imagine how many cups of spinach you would need to consume to meet the same level as meat.

Accordingly, those with strict dietary restrictions are often the more common victims of vitamin B3 deficiency. In such cases, taking vitamin B3 supplements is the go-to solution that is often highly recommended by doctors and nutritionists.

But, before you go ahead and purchase vitamin B3 pills or powders, it’s crucial to learn more about its side effects, long-term benefits, and the correct way to consume them. Read on below to find out more about vitamin B3 niacin, and don’t forget to consult with your doctor first before incorporating these supplements into your daily diet.

Niacin Side Effects

Due to its water-soluble nature, consuming niacin in large amounts through food is safe and is not likely to cause any serious problem. After all, any excess of vitamin B3 in the body will naturally be flushed out in the form of urine.

However, it is a completely different story when it comes to taking vitamin B3 supplements in pill or powder form. Like any form of medication out there, taking vitamin B3 may have some side effect. Below are some of the most common vitamin B3 side effects:

  • Headaches
  • Dizziness and nausea
  • Blurred vision
  • Gas and belching
  • Vomiting
  • Diarrhea
  • Sweating or chills
  • Muscle pain and leg cramps
  • Low blood pressure

If you are experiencing the symptoms above and you suspect that it is due to the consumption of a vitamin B3 supplement, discontinue use and contact your doctor immediately.

Niacin Flush

The correct dosage of niacin depends on a variety of factors – age, sex, and other health conditions need to be considered before deciding the proper dosage. Some situations may call for a higher albeit safe amount of niacin, but it does not come without any side effects.

The niacin flush is perhaps one of the most common vitamin B3 side effects there is; almost everyone who takes a large amount of niacin (about 250 milligrams or more) may experience the said flush. A niacin flush usually happens after 10-20 minutes after consumption when niacin causes the skin’s blood vessels to dilate, allowing more blood to rush through. As a result, the skin becomes red and is followed by a burning or itching sensation.

Flushing is almost always more evident on the face, but it can also occur in the upper body as well and most notably around the neck. The good news is that the flush disappears typically within an hour or two, and it gets better over time as well.

If you find niacin flushes to cause a great deal of discomfort, then you may want to try a couple of preventive measures. The most obvious solution is to decrease the dose of niacin. The average adult requires 15 milligrams of niacin per day, so any amount beyond this may not be necessary. Another option may be to utilize time-release forms of niacin. This allows the niacin contents in the body to metabolize slower than regular niacin.

Some may suggest taking aspirin at least 30 minutes before taking the niacin supplement. This may help lessen the discomfort that comes along with a niacin flush although some have reported this method to be ineffective.

Niacin Deficiency

A vitamin B3 deficiency can cause serious headaches.

As mentioned above, the body requires niacin for a variety of bodily functions. Not only does it help your body convert macronutrients to energy, but it is also needed for your digestive system and nervous system to function as it should. Sadly, there are quite a lot of people who have niacin deficiency in the world – particularly among those who live in underdeveloped countries.

Niacin deficiency is brought about by the lack of a healthy diet. Since most foods already have a good amount of niacin, supplementing the body with the right amount of niacin shouldn’t be that much of a problem. As long as you are eating right and making healthy lifestyle choices, you are not likely to develop a niacin deficiency.

In most parts of the world, however, alcoholism is the number one cause of niacin deficiency. Scientific research has found that alcohol inhibits the proper absorption of niacin and tryptophan in the body, resulting in a significant lack of vitamin B3. Some digestive disorders and medication may also be an underlying cause although they are not as common.


Pellagra is a disease that is caused by niacin deficiency. Those with this condition have digestive issues, inflamed skin, and they may also have some mental impairments. Other symptoms may include diarrhea, dementia, and canker sores. Again, this condition is quite rare and is currently an issue found in underdeveloped countries.

Niacin Benefits

Getting enough vitamin B3 has a lot of health benefits.

Regulates Blood Sugar Levels

Niacin is said to have unique properties that can help improve the function of beta cells which are responsible for insulin production in the body. Because of this, niacin has always been considered as a viable treatment for diabetes. Vitamin B3 helps the body balance blood sugar levels and control the many symptoms of diabetes.

And, because niacin can also help lower high blood cholesterol and the risk of heart disease, vitamin B3 may be beneficial for diabetics who are at risk for both conditions. On the downside, however, niacin has also been associated with complications regarding rising blood sugar levels. Before taking niacin supplementation, it is best to speak with a doctor to avoid unwanted side effects.

Protection From Heart Disease

Apart from lowering bad cholesterol, niacin also promotes heart health by reducing the possibilities of contracting atherosclerosis or the hardening of the arteries which leads to coronary heart disease, but that’s not all…

Those who have suffered from a cardiac arrest, a heart attack, or other forms of heart disease in the past may also benefit from vitamin B3. It is said that niacin can effectively risk the re-occurrence of such attacks by lowering the levels of low-density lipoproteins in the blood. These lipoproteins have been discovered to be one of the most significant risk factors for heart disease.

Reduces Erectile Dysfunction

Vitamin B3 does not only contribute to the overall health of the heart, but it can also reduce erectile dysfunction in men. Erectile dysfunction, otherwise known as impotence, refers to the inability for a man to sustain an erection.

Impotence is more common among men at a certain age. But the truth is, it can happen at any age. There is a wide variety of reasons that can cause impotence in men. Some of which include bad blood circulation, stress, and illness.

According to some studies, taking vitamin B3 as a supplement can help prevent erectile dysfunction due to its vasodilator characteristics. When niacin improves blood flow throughout the body, impotence may be resolved. Additionally, studies also state that 1,500 milligrams of niacin are sufficient enough to improve sexual function in men with erectile dysfunction.

Promotes Healthy Joints

A few studies have discovered that an increased intake of niacin can provide positive effects on joint pain. Vitamin B3, in the form of niacinamide, is said to be effective in enhancing joint mobility. Not only does it reduce joint pain, but it can also decrease inflammation that’s common in joint conditions such as osteoarthritis.

Some doctors have also prescribed niacinamide to decrease the intake of painkillers or other medications for arthritis. Since niacinamide has been proven to reduce swelling and improve flexibility, it is often the more preferred type of medication for joint pain. Moreover, thanks to the inflammation-reducing properties of niacin, it is also used to decrease the symptoms of arthritis and to build strength in the joint cartilage.

Great for Healthy Skin

Earlier, we’ve learned that niacin also has anti-inflammatory properties. That being said, niacin in the form of niacinamide is also utilized for improving skin health and for treating various skin-related conditions such as acne and inflammation.

For this purpose, niacin is not usually taken in pill or powder form but rather, it is applied directly onto the skin. Today, there are many body gels and skin creams containing niacin for topical uses. Additionally, it is also said that niacin is useful in treating bullous pemphigoid and granuloma annulare both of which involve inflamed skin, painful blistering, and may even lead to infection without proper care.

Prevents Birth Defects

Nicotinamide adenine dinucleotide (NAD) are molecules that are crucial for storing energy in the body and for the DNA synthesis in cells. Vitamin B3 niacin, on the other hand, plays an integral role in preventing NAD defects. This is particularly important information among pregnant women because according to a study last 2017, a disruption in the NAD molecule creation may cause malformations in both humans and mice.

Alternatively, vitamin B3 supplementation during pregnancy is the solution to prevent such malformations caused by NAD defects. However, more studies are required to prove a solid connection between vitamin B3 and NAD levels. But even so, it is always healthy to provide the body with the right amount of vitamin B3 and most especially among pregnant women.

Niacin Overdose

As we’ve learned earlier, ingesting huge quantities of niacin through food is typically safe and not a cause for concern. Overdosing on supplements, on the other hand, may cause adverse effects on one’s health.

An average person needs about 15 milligrams of vitamin B3 per day. But, this amount varies according to a person’s sex, age, and whether or not they are pregnant.

Meanwhile, for those that require supplementation, most prescriptions start at 100 milligrams, and it is split into three doses throughout the day. In some cases, the dosage may be increased to the maximum at 1000 milligrams per day. Anything beyond 2000 milligrams a day is not recommended as this may cause severe side effects. Fatalities caused by niacin overdose are not common, but it does not mean that it is impossible.

Apart from the vitamin B3 side effects listed above, severe cases of niacin overdose may lead to the following consequences:

  • Rapid heartbeats (also known as tachycardia) and difficulty breathing
  • Severe hypotension
  • Peptic ulcers
  • Gout

Niacin for Cholesterol

Vitamin B3 can lower cholesterol levels.

According to research, taking vitamin B3 niacin may be very advantageous to those with an increased risk for stroke, heart attack, and other types of heart-related diseases. Such illnesses are usually caused by having an imbalanced LDL cholesterol and HDL cholesterol.

Having higher levels of bad LDL cholesterol and lower HDL cholesterol or increased triglyceride levels pose a significant threat to the heart. But, the good news is that niacin has been said to be a viable solution for lowering cholesterol levels. Research shows that niacin can boost the levels of good HDL cholesterol while also reducing triglycerides at the same time.

Niacin for Anxiety

Anxiety is a common emotion human beings experience occasionally. However, when it comes to anxiety disorders, the feeling becomes too intense that it can cost someone their quality of life. Today, several types of disorders related to anxiety. Conditions such as Social Anxiety Disorder, Phobias, and Panic Disorder are some of the most common types.

Although medical experts know the causes of such disorders, there are many cases in which the causes are still unknown. Those who have these conditions often have to rely on different forms of therapy, counseling, and even lifestyle and dietary improvements.

However, recent studies believe that a certain vitamin may be missing for those who are suffering from anxiety disorders. Many believe that niacin is the answer because of its antidote-like characteristics towards adrenaline, which is produced in excess among those who have anxiety disorders.

Moreover, researchers also have a reason to believe that niacin can help reduce anxiety and depression while also enhancing better sleep quality and sleeping patterns. Studies took note of niacin’s ability to increase blood flow, lower blood pressure, and remove excess adrenaline. Because of this, they also believe that niacin contributes to the feeling of relaxation, with hopes that stress can be eliminated for those with an anxiety disorder.


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