What is Niacin Toxicity?
With so many people taking a lot of supplements these days, it’s important to be cautious of potential overdoses, like niacin toxicity. Niacin, also known as Vitamin B3, is a necessary nutrient that we usually get from our food. This vitamin, in its forms called nicotinic acid and nicotinamide, is mostly broken down in the liver.
Nicotinamide is mainly used today to treat a lack of niacin in the diet. For many years, nicotinic acid was used to treat high levels of fats in the blood. However, this shifted as statin drugs, a type of medicine used to lower cholesterol levels, became the primary treatment. Recent studies suggest that adding niacin to statin treatments does not significantly improve the results. The following discussion will focus on the different symptoms and problems caused by excessive niacin.
What Causes Niacin Toxicity?
Niacin deficiency, although less common today, was once the root cause of a disease called pellagra. This deficiency has also been noted to increase the risk of developing diabetes in people without the disease and can increase the blood sugar levels in those already diagnosed with diabetes. It’s important to note that taking too much niacin can cause serious side effects such as lowered blood pressure, damage to the liver, and failure of multiple organs.
Energy drinks often contain high levels of vitamins, including niacin. There have been individual instances of acute hepatitis, an inflammation of the liver, that seems to be linked to the high levels of niacin in these drinks. Additionally, some people have tried to use niacin in an attempt to pass drug tests for jobs, based on an online theory that it can speed up metabolism to help get rid of toxins. This has also resulted in cases of toxicity.
Risk Factors and Frequency for Niacin Toxicity
Niacin poisoning statistics from the 2018 report of the American Association of Poison Control Center’s National Poison Data System revealed that there were about 792 individual cases. No difference was noted between males and females. The majority of cases occurred in two different age groups: 248 patients were five years old or under, and 397 patients were 20 years old or older. Out of these, 405 exposures were accidental, and 150 were intentional. A total of 232 adverse reactions were recorded, with 227 people needing treatment in a hospital.
- About 792 individual cases of niacin poisoning were recorded in 2018.
- No difference was noted between males and females in the instance of poisoning.
- The majority of the cases were in two age groups: under five years and over 20 years.
- Out of the total cases, 405 were accidental and 150 were intentional.
- 232 adverse reactions to niacin were recorded.
- 227 patients received treatment in the hospital.
- Among the outcomes, 71 individuals experienced no problems, 255 had minor toxicity, 61 had moderate toxicity, one experienced a severe reaction, and thankfully, no one died.
Signs and Symptoms of Niacin Toxicity
People who are taking additional products that contain niacin may experience a number of side effects. They may feel hot and itchy, feel sick or actually vomit, get headaches, feel dizzy or have stomach pain. It’s important for a patient to tell their doctor about all products they are taking, as these symptoms may not naturally lead a doctor to ask about niacin use. In addition, the patient’s blood pressure may be lower than normal, their skin might look flushed, they might have an enlarged liver, appear yellow due to jaundice, or show signs of confused thinking. These symptoms might cause the doctor to think the patient is having a severe allergic reaction.
- Feeling hot and itchy
- Feeling sick or vomiting
- Headaches
- Feeling dizzy
- Stomach pain
- Lower than normal blood pressure
- Flushed skin
- Enlarged liver
- Yellow skin or eyes (jaundice)
- Confused thinking
Testing for Niacin Toxicity
If your doctor suspects you may have consumed too much niacin (also known as Vitamin B3), they might conduct several tests to better understand your condition and rule out other issues. These tests can include:
1. A 12-lead electrocardiogram (ECG): This is a test that measures the electrical activity of your heart to show whether it is working normally. It can reveal any abnormal rhythms (arrhythmias), a condition called QT-prolongation which can cause erratic heart beats, or QRS-widening which may indicate a heart block or damage.
2. Blood gas and a chemistry panel: A blood gas test measures the amount of oxygen and carbon dioxide in your blood. The chemistry panel is a blood test that checks your body’s electrolyte balance, as well as the functioning of your kidneys and liver.
3. A complete blood count, liver panel, and prothrombin time: This battery of tests can give the doctor information on the overall status of your health, specifically your blood cells, liver function, and how quickly your blood clots (prothrombin time).
In cases of suspected chemical or drug overdoses, it’s not uncommon for doctors to test for multiple substances that you might have ingested at the same time.
There’s also a specific test for the level of nicotinic acid (another name for niacin) in your body. However, the results from this test usually take some time to come back, so it might not influence the initial measures taken to treat you. This means your doctor will diagnose and decide on a treatment based on your health condition and symptoms, instead of waiting for the test results.
Most of the time, imaging tests like X-rays or CT scans aren’t useful for diagnosing niacin toxicity. It’s also worth noting that before diagnosing you with niacin toxicity, your doctor will rule out other possible causes of your symptoms. This means that the diagnosis of niacin toxicity often comes after other conditions have been excluded.
Treatment Options for Niacin Toxicity
When you arrive at the emergency department, the medical team will quickly evaluate your basic vital signs like your airway, breathing, and circulation. They’ll also check your blood sugar, oxygen levels, and body temperature right away. If needed, they can help warm you up if you’re too cold, give you glucose (a type of sugar) if your blood sugar is too low, and provide fluids straight into your veins to help replace any lost body fluids.
In some rare cases, they might need to use special treatments to restore your body’s balance, like a bicarbonate drip (which helps adjust the level of acid in your blood) or drugs that help increase your blood pressure. If your condition is severe, you might receive fresh frozen plasma or packed red blood cells through a blood transfusion.
If the medical team notices signs of severe liver toxicity, they’ll involve a specialist in digestion and liver diseases (a gastroenterologist) to decide if you need a medicine called N-acetylcysteine that can sometimes help the liver. In very extreme cases, they might even consider a liver transplant.
You might also experience symptoms like your skin becoming red and warm (a condition known as flushing), which can be uncomfortable. This symptom usually goes away on its own and does not need medication. However, if needed, aspirin or similar drugs can help reduce these symptoms. But in most cases, simply stopping the product causing these symptoms, providing reassurance, and arrangement for follow-up care will be all you need for treatment.
What else can Niacin Toxicity be?
When testing for niacin toxicity, different conditions might be considered by doctors because they can also cause flushing, or a warm, reddening of the skin. These conditions may or may not also lead to symptoms related to the stomach or intestines:
- Anaphylaxis, a severe allergic reaction, which should be suspected if flushing is accompanied by swelling under the skin, particularly around the eyes and lips.
- Emotional distress conditions like a Panic attack, or physical conditions like thyroid storm, hyperthyroidism, or rosacea.
- Allergies to food or preservative.
- Reactions to certain medications, like metronidazole.
- Scombroid poisoning, caused by eating spoiled fish.
- Taking certain heart medications.
- Reactions to antibiotics (like ceftriaxone, vancomycin, amphotericin-B).
- Side effects of erectile dysfunction drugs.
- Bites from a Black widow spider.
- Anticholinergic toxicity from medications and certain plants (like jimsonweed and deadly nightshade), which can cause flushing.
- Serotonin syndrome, a drug-related condition that can cause flushing, confusion, muscle twitching, high body temperature, and quick heart rate.
In instances where niacin toxicity might cause liver damage, it’s also important for doctors to consider other causes of elevated liver function tests such as:
- Drugs like amiodarone, isoniazid, and methotrexate.
- Over-the-counter medications like acetaminophen.
- Consumption of poison mushrooms like ‘death cap’.
- Misuse of alcohol.
What to expect with Niacin Toxicity
Flushing, or feeling warm and possibly red in the face and neck, tends to resolve on its own and usually doesn’t need any treatment. Even patients who experience significant increases in liver function tests due to the use of niacin – a vitamin used to lower cholesterol and fats in the blood – generally have positive outcomes as long as they stop taking the vitamin, especially certain types known as sustained-release (SR) formulations.
Possible Complications When Diagnosed with Niacin Toxicity
Niacin toxicity can cause side effects like flushing, headaches, lightheadedness, itching, nausea, and vomiting. These effects go away when the person stops taking the supplement. More serious issues like low blood pressure, coagulopathy (a condition that prevents the blood from clotting properly), and metabolic acidosis (a condition that causes too much acid in the body fluids) can improve with supportive care. However, in some rare instances, niacin toxicity can cause liver damage. This can result in severe liver failure which may even require transplantation or can lead to death.
Side Effects of Niacin Toxicity:
- Flushing
- Headaches
- Lightheadedness
- Itching
- Nausea
- Vomiting
- Low blood pressure
- Coagulopathy
- Metabolic acidosis
- Liver damage
- Severe liver failure
- Potential death
Preventing Niacin Toxicity
It’s very important for the doctor to ask the patient about any non-prescription medications or supplements they are taking. This includes finding out what specific types of vitamins they are taking, especially if they are using a type that releases slowly into the body. Understanding why the patient is taking these supplements is also crucial, particularly if they decided to start taking them based on information they found online.
