Vitamin B3 (Niacin)

What is niacin?

Niacin excess is likely

Symptoms of chronic niacin toxicity

Symptoms of acute niacin toxicity

Minimising or removing niacin

References

Thank you to Grant Genereux for identifying what may be a widespread toxicity. (1)

What is niacin?

Niacin, a water-soluble B vitamin, is essential for human health, critical for energy metabolism, DNA repair and cellular function. Like all other nutrients, it is possible to have too little or too much niacin. Severe niacin deficiency causing pellagra is very rare. Problems caused by excess niacin are widespread and common, straining the liver, disrupting methyl groups and causing the symptoms listed below.

The main food sources of niacin are meat, fish, whole grains, legumes, root vegetables and nuts. The human body can also synthesise niacin from tryptophan, acquired mostly from dairy or poultry, with 60 mg of tryptophan making approximately 1 mg of niacin.

Niacin modulates lipogenesis - it blocks the sebaceous glands from producing sebum. The face, scalp, chest and hands have the highest concentrations of sebaceous glands. The meibomian glands of the eyes are also sebaceous glands. Niacin has been used since the 1950s as the go-to drug to suppress the lipogenesis of LDL cholesterol.

Nicotinic Acid, a carboxylic acid form of niacin, naturally occurs in some foods and is used as a supplement to control excessive blood fats. It is known for its characteristic niacin flush.

Nicotinic acid may cause more retinoic acid to enter cells by activating the hydroxycarboxylic acid receptor 2 in cells. (2) This is very important when considering vitamin A toxicity, also identified and researched by Grant Genereux.

Nicotinamide is another compound closely related to niacin. It is a direct precursor to NAD+ (nicotinamide adenine dinucleotide), vital for cellular processes and is commonly used in supplements and skincare, especially for anti-ageing.

Niacin excess is likely

The NIH Recommended Dietary Allowance (RDA) of niacin is 14-16 mg/day for adults, with an Upper Tolerable Intake Level (UL) of 35 mg/day for adults.

High-dose niacin supplements (typically 500-3000 mg/day of nicotinic acid or nicotinamide) are used for cholesterol management, skin health and in health "detox" regimens. Nicotinamide is also used in anti-aging protocols of 500-1000 mg/day for NAD+ boosting.

The USA, Canada and a few North African countries mandate adding niacin to flour. This probably explains why people frequently report that they become ill when eating products containing wheat flour in America, but can eat bread, croissants and cakes in Europe with no ill effect.

Gluten intolerance, apparently so widespread in America and among people consuming modern diets, is probably niacin toxicity. Severe stomach pain is a niacin toxicity symptom.

I believe the evidence for setting a UL of 35 mg/day is weak, and the symptoms caused by long term ingestion at this level are serious.

It is likely that most people on a modern diet are getting an excessive amount of niacin.

Symptoms of chronic niacin toxicity

• Dry skin, itching skin, dandruff, seborrheic dermatitis. Dandruff (pityriasis capitis) and seborrheic dermatitis on the scalp are at epidemic levels in the USA. (3)
• Dry eyes. Dry eye diseases are at epidemic levels in the USA. (4)
• Light-gray-coloured stools.
• Cough.
• Frequent urination, darker urine.
• Loss of appetite.
• Diarrhoea, stomach pain. (Mis-diagnosed gluten intolerance.)
• Yellow eyes or skin.
• Fever, feeling of warmth.
• Flushing or redness of the skin, especially on the face and neck.
• Headache.
• Nausea or vomiting.
• Runny nose, stuffy nose, sneezing.
• Dizziness or faintness.
• Joint pain, cramping, muscle ache, pain in the side or lower back.
• Oedema, swelling of the feet or lower legs.
• Unusual thirst.
• Tiredness or weakness.
• Irregular heartbeat, or too fast or too slow heartbeat.

Symptoms of acute niacin toxicity

• Flushing of the skin. The classic B3 flush.
• Stomach upset or pain (which usually subsides within a few weeks).
• Headache.
• Dizziness.
• Blurred vision and very dry eyes.
• Liver damage.

Minimising or removing niacin

• Read food labels carefully. Strictly avoid any food that has niacin added to it, such as all products with wheat flour in the USA.
• Avoid any supplement that has niacin added as one of the ingredients. Avoid nutritional yeast (as opposed to brewer's yeast that is more like a traditional food). Nutritional yeast often comes in the form of dried flakes, and contains a heavy addition of niacin. Avoid niacin supplements, such as Niacinol, Niacor, Niaspan, Nicotinex and Slo-Niacin.
• Sodium bicarbonate (baking soda). Sodium bicarbonate is useful in neutralising circulating retinoic acid, so it is likely to have a similar mechanism to neutralise circulating niacin. RCOOH + NaHCO3 -> RCOONa + H2O + CO2. A daily dose of baking soda may help reduce the destructive inflammation of autoimmune diseases like rheumatoid arthritis. (1, 5, 6, 7)

Your comments about any of your experiences - positive or negative - with your use of niacin are welcome at Grow Youthful. I am always curious about your use of and experience with natural remedies, and your feedback is very welcome.

References

1. Grant Genereux. Niacin: Is it another bogus vitamin? 13 May 2024. ggenereux.blog.

2. Markovics A, Toth KF, Sos KE, Magi J, Gyongyosi A, Benyo Z, Zouboulis CC, Biro T, Olah A. Nicotinic acid suppresses sebaceous lipogenesis of human sebocytes via activating hydroxycarboxylic acid receptor 2 (HCA2 ). J Cell Mol Med. 2019 Sep;23(9):6203-6214. doi: 10.1111/jcmm.14505. Epub 2019 Jul 5. PMID: 31273921; PMCID: PMC6714165.

3. Manuel F, Ranganathan S. A new postulate on two stages of dandruff: a clinical perspective. Int J Trichology. 2011 Jan;3(1):3-6. doi: 10.4103/0974-7753.82117. PMID: 21769228; PMCID: PMC3129121.

4. Dana R, Meunier J, Markowitz JT, Joseph C, Siffel C. Patient-Reported Burden of Dry Eye Disease in the United States: Results of an Online Cross-Sectional Survey. Am J Ophthalmol. 2020 Aug;216:7-17. doi: 10.1016/j.ajo.2020.03.044. Epub 2020 Apr 8. PMID: 32277941.

5. Zhang W, Zhang L, Huang Z, Cai S, Ye Z, Chen Z, Huang J, Liu Z. The Effects of Oral Sodium Bicarbonate on Renal Function and Cardiovascular Risk in Patients with Chronic Kidney Disease: A Systematic Review and Meta-Analysis. (2021). Therapeutics and Clinical Risk Management, 17, 1269-1282.

6. Robey IF, Baggett BK, Kirkpatrick ND, Roe DJ, Dosescu J, Sloane BF, Hashim AI, Morse DL, Raghunand N, Gatenby RA, Gillies RJ. Bicarbonate increases tumor pH and inhibits spontaneous metastases. Cancer Res. 2009 Mar 15;69(6):2260-8. doi: 10.1158/0008-5472.CAN-07-5575. Epub 2009 Mar 10. PMID: 19276390; PMCID: PMC2834485.

7. Sarah C. Ray, Babak Baban, Matthew A. Tucker, Alec J. Seaton, Kyu Chul Chang, Elinor C. Mannon, Jingping Sun, Bansari Patel, Katie Wilson, Jacqueline B. Musall, Hiram Ocasio, Debra Irsik, Jessica A. Filosa, Jennifer C. Sullivan, Brendan Marshall, Ryan A. Harris, Paul M. O'Connor. Oral NaHCO3 Activates a Splenic Anti-Inflammatory Pathway: Evidence That Cholinergic Signals Are Transmitted via Mesothelial Cells. The Journal of Immunology, 2018; ji1701605.