There’ve been significant changes in vitamin B3 intake throughout history. While food of animal origin, especially meat, had only been accessible in a limited supply, nowadays meat consumption has multiplied in most countries apart from some of the developing world. 

Researchers believe that adequate vitamin B3 supplementation can significantly improve general well-being, but both over- and underdosing the vitamin can cause problems. Vitamin B3 deficiency remains a concern in many developing countries with mainly corn- or rice-based diets; on the other hand, wealthy nations tend to eat too much vitamin B3 rich food. 

How did meat consumption change through time? 

Following the development of agriculture, human population grew, but most people’s diet  contained less meat than previously. Meat consumption has been increasing significantly from the 19th century: in Great Britain, it doubled between 1850-1960, then doubled again between 1960-2010. In most developed countries, average meat consumption is around 120 kg per year, while in developing countries, it’s around 20 kg per year. It’s possible that increased vitamin B3 supplementation through meat consumption rendered diseases related to malnutrition much less common while diseases of civilization caused by overnutrition increased in occurrence. 

What have we gained from increased meat consumption? 

As meast consumption grew, human’s height and intelligence increased, while the occurrence of various infectious diseases decreased. On the other hand, the number of degenerative illnesses such as diabetes, Parkinson’s disease and cancer became significantly higher, as well as that of patients with allergies or autoimmune disease. Researchers hypothesize that to a certain extent, these findings can be explained through the monumental changes in vitamin B3 intake. 

What adverse effects can it have? 

Permanent high dose vitamin B3 consumption made the symbiotic bacteria producing B3 unneeded, but without them, the immune system often has an unproportionally intense immune response to harmless environmental proteins and the body’s own proteins as well. It’s because of this that in countries where TB and other infectious diseases are still common, autoimmune diseases are remarkably rare; and where they are not present, autoimmunity is significantly more frequent. 

Though the “hygiene hypothesis” is still a heavily contested concept, it relies on abundant scientific evidence. According to the hypothesis, certain microorganisms which have been evolving alongside humanity help us develop immune tolerance in childhood. Losing these “old friends” can make us highly susceptible to various allergies. 

Besides this, consistently high dose vitamin B3 supplementation (for example, the combination of a meat rich diet with dietary supplements) increases the function of the NNMT enzyme. High levels of NNMT enzyme can be correlated with Parkinson’s disease, metabolic syndrome and certain types of cancer. In addition, chronically high doses of vitamin B3 intake can negatively impact certain metabolic functions, which can change the composition of the intestinal flora for the worse. 

Summary 

It’s quite surprising how complex effects a single vitamin can have on the body. While vitamin B3 intake is critical, it’s possible that people living in developed countries are overdosing, which can have effects just as negative as underdosing which is common in developing countries. 

To maintain proper vitamin B3 levels, it’s likely wise not to eat too much meat; if one’s diet is rich in meat, they should not supplement vitamin B3 through additional sources. In the meanwhile, if one’s diet is mainly plant based, it’s advisable to supplement 15-20 mg of vitamin B3 daily.