Jonathan Bortz MD

Jonathan’s background as a practicing diabetes specialist for 15 years and 17-year career developing nutritional prescriptive products for the pharmaceutical industry has contributed to his ability to understand nutrients, how they work and why they are important.

Over the years he has acquired broad and in-depth knowledge in minerals, essential fatty acids and other nutrients, but has special expertise in Vitamin B12 and choline metabolism. He is often asked to speak at national and international venues to articulate why B12, folate and choline are so important to gene function, brain development, liver and cardiovascular health. He applies pharmaceutical standards to nutrient science and has developed a unique ability to translate complicated concepts into simple promotional messages that resonate with practitioners and consumers. He has developed dozens of innovative nutritional products, of which many are category leaders in the US. Jonathan obtained his medical degree from the University of the Witwatersrand Medical School in South Africa and did his fellowship in Endocrinology at Washington University in St. Louis, MO.

Recent Articles from

Jonathan Bortz MD

X Fact

Discovery of Vitamin B12
Karl Folkers

In 1926, Harvard physicians discovered that eating half a pound of liver daily would prevent Pernicious Anemia. The hunt was on to identify the compound in liver that was responsible. In 1947, Karl Folkers (a scientist at Merck) isolated the tiny red crystals of vitamin B12. 'Extrinsic Factor' now had a name.

See X Fact
Extrinsic Factor

It was first noticed in 1929 that giving beef alone to Pernicious Anemia patients did not improve the anemia, but when given with human gastric juice, it did. Giving gastric juice alone (without beef) didn't help either. In 1936, the scientist, W.B Castle called the substance in beef 'Extrinsic Factor' and the substance in gastric juice 'Intrinsic Factor'. They only work when given together. Today we know Extrinsic Factor by a different name, vitamin B12.

See X Fact

Recent Articles from

Jonathan Bortz MD

Xeragenx Blog

More Than Methylation: The Crucial Role Of Choline With Dr. Jonathan Bortz

In this episode, Dr Jonathan Bortz discusses his journey into developing pharmaceuticals and supplements, and how it brought him to look at choline in a different light. He talks about the story of choline as a “one carbon metabolism,” as well as the various uses of choline in the body, including its role in methylation, genetics, and non-alcoholic fatty liver disease (NAFLD).

Read Full Article
What's IF?

Intrinsic Factor (IF) is a protein made in the stomach that is essential for ensuring the natural absorption of vitamin B12.

Read Full Article