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X Fact
July 3, 2020
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Why Vitamin B12 was Called 'Extrinsic Factor' by the Scientist Who Predicted That it Must Exist

By:
Jonathan Bortz MD

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.

Sources:

jamanetwork.com

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Words You May Not Know
Extrinsic Factor
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Extrinsic Factor

Vitamin B12

Intrinsic Factor
Quick View

Intrinsic Factor

Intrinsic factor is a protein that helps your intestines absorb vitamin B12. It is made by cells in the stomach lining. Intrinsic factor binds to vitamin B12. After attaching, intrinsic factor and B12 travel to the intestines to be absorbed into the bloodstream. Vitamin B12 is needed for red blood cells to form and grow‍‍.

Who Wrote This X Fact
Jonathan Bortz MD
Bio Quick View

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.

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Xeragenx LLC is a biotechnology company specializing in the development, and supply of plant-derived recombinant human Intrinsic Factor (rh-IF) for multiple applications, including use in foods, beverages and dietary supplements.  All information on this website is provided for informational and educational purposes only, and is intended solely as a business-to-business (B2B) communication. This information is not intended for use by consumers and should not be construed as medical advice.

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