The maximum safe dose of niacin from supplements is 35 mg a day. Much higher dosages may cause side effects! Too much niacin from food doesn’t cause toxicity, though.
Health benefits of niacin (vitamin B3)
Niacin is a water-soluble B-vitamin, also known as vitamin B3. It’s crucial for good health. Above all, niacin is necessary for a healthy heart. It improves endothelial function (the thin membrane inside the heart and blood vessels), reduces atherosclerosis progression, and prevents vascular inflammation.[1,2,3]
Also, niacin increases the good HDL cholesterol, while reducing the dangerous LDL cholesterol and triglycerides! Hence, niacin is usually used for the reduction of high cholesterol levels. Pharmacological doses between 1,000 and 3,000 mcg have beneficial effects.
In fact, niacin has been found to decrease cardiovascular mortality. Especially, when used in combination with statin drugs.
Moreover, niacin has a neuroprotective effect. It plays a key role in the proper functioning of the central nervous system. Thus, niacin may decrease the risk of age-associated neurological disorders, such as Alzheimer’s or Parkinson’s disease.
Additionally, niacin is beneficial for people with diabetes, chronic kidney disease, and arthritis.
Last, but not least, adequate amounts of niacin are necessary for weight loss. Niacin improves insulin sensitivity and plays a key role in the regulation of circadian rhythm and metabolism!
What’s the recommended daily intake?
The recommended daily intake of niacin is 16 mg for men and 14 mg for women. Only pregnant and lactating women need higher doses of 18 mg and 17 mg, respectively.
What’s the maximum safe dosage of niacin from supplements?
The maximum safe dosage of niacin from supplements is 35 mg for adults, 30 mg for teenagers, and 10-20 mg for children, depending on the age.
Skin flushing is the most common side effect when too much niacin from supplements is consumed.
Only patients under medical supervision could receive much higher doses.
You should consult your physician before taking niacin supplements. Especially, if you’re pregnant, take medication, or have a medical condition.
Can I get too much niacin from food?
On the contrary, there hasn’t been established a maximum safe dose of niacin from foods. Following a diet high in niacin won’t cause any side effects.
In fact, there is a wide variety of foods high in niacin. Animal-based food sources high in niacin are turkey, beef, and fish. These foods provide about 5-10 mg of niacin per serving.
Beans, seeds, nuts, whole grains, mushrooms, and nutritional yeast are excellent plant-based sources of niacin. They provide about 2-5 mg of niacin per serving. Nutritional yeast is among the richest foods in niacin. It provides 15 mg of niacin per serving!
Moreover, there are many fortified foods with niacin, which boost the daily intake. Most noteworthy, niacin in fortified foods is highly bioavailable.
Side effects of too much niacin
Most niacin supplements contain between 50-500 mg of niacin per serving. But, a dose of 500 mg is about 3,000% and 1,300% higher than the recommended daily and maximum safe dose, respectively!
Even smaller niacin doses of 50 mg in the form of nicotinic acid may cause skin flushing, as it increases the blood flow of small subcutaneous blood vessels. The flushing may be accompanied by a burning or itching sensation.
But, more serious side effects may occur. For instance, headache, rash, dizziness, and a decrease in blood pressure are common side effects of niacin overdose.
If you experience adverse effects, you should immediately talk to your healthcare provider. Furthermore, you should decrease the daily dose. Also, if you take niacin supplements in the form of nicotinic acid and experience side effects, you could take them with food.
Additionally, much higher doses of 3,000 mg a day may cause more serious adverse effects, such as impaired glucose tolerance, insulin resistance, nausea, heartburn, abdominal pain, and even blurred vision.
Hence, you should take these pharmacological doses only under medical supervision.
Moreover, the American College of Cardiology and the American Heart Association recommend measuring hepatic transaminase, fasting blood glucose, hemoglobin A1C, and uric acid levels before starting therapy with extremely high doses of niacin.
Furthermore, if you take high doses of niacin from supplements, you should avoid alcohol. Alcohol seems to increase the risk of flushing. Also, people who overconsume alcohol for years shouldn’t take high doses of niacin, as it may further damage their liver!
Last, but not least, pregnant women shouldn’t take high dosages of niacin, without consulting their physician. High doses of niacin may harm the fetus.
Which niacin supplement has fewer side effects?
Niacin in dietary supplements is mainly found in two forms; nicotinamide and nicotinic acid. High doses of both niacin forms can cause adverse effects, though.
As a rule of thumb, nicotinamide is more tolerable than nicotinic acid. The same dosage has fewer adverse effects than nicotinic acid. For instance, it doesn’t cause skin flushing.
Side effects, such as nausea and vomiting, may occur at extremely high nicotinamide intakes of 3,000 mg per day, though.
In any case, you shouldn’t exceed the maximum safe dose of niacin without consulting your physician.
Do I need high niacin doses from supplements?
Healthy people who follow a well-balanced diet don’t need niacin supplementation. On the other hand, poor diet, alcohol abuse, medication, and disease are common reasons of niacin deficiency.