Riboflavin is the ultimate fat-burning nutrient. It makes even a bad MTHFR work right, and it keeps you looking young and beautiful forever.

Here's everything you need to know about why you should manage your riboflavin status and how to do it.

In this podcast I join with Alex Leaf of Examine.Com. I focus on what riboflavin is and what it does, while Alex focuses on riboflavin supplements.

Going into this podcast I changed my mind about three important things:

• While I had always discussed riboflavin as relevant to methylation and MTHFR, I had kept it in the back seat in my methylation protocol. Half way through recording this podcast I realized that it really deserves a front seat in my MTHFR protocol. In fact, it may be the case that there's nothing wrong with the common MTHFR polymorphisms at all and that they only appear to hurt MTHFR activity because most of us aren't getting enough riboflavin. And why aren't we? Liver. Liver. We just have to eat liver.
• In Testing Nutritional Status: The Ultimate Cheat Sheet, I had included HDRI's erythrocyte glutathione reductase activity test as test for assessing riboflavin status. After doing the research for this podcast, I am now convinced that this test is only reliable as a marker of riboflavin status when the lab tests the enzyme activity with and without the addition of riboflavin, which HDRI doesn't do. I will be revising the cheat sheet soon to rely solely on LabCorp's whole blood riboflavin test for assessing riboflavin status.
• I have, for years, believed that riboflavin 5'-phosphate (aka, flavin mononucleotide or FMN) supplements are better than plain old riboflavin, especially for people who are hypothyroid or have low adrenal status, since these conditions impair the activation of riboflavin to it's 5'-phosphate form. After doing the research for this podcast I now believe that for healthy people it makes no difference and that for people with small intestinal pathologies, the cheaper, less fancy, plain old "riboflavin" is likely to be more effective.

In this podcast we being by considering the fictional stories of people who seem to have little in common. We then explain their stories by looking at the signs and symptoms of riboflavin deficiency. We consider the science of what riboflavin is, how it is used by the body, what it does for us, how to have great riboflavin status, and how to become deficient. We round this out with an extensive discussion of riboflavin supplementation.

This episode is brought to you by Ancestral Supplements' "Living" Collagen. Our Native American ancestors believed that eating the organs from a healthy animal would support the health of the corresponding organ of the individual. Ancestral Supplements has a nose-to-tail product line of grass-fed liver, organs, "living" collagen, bone marrow and more... in the convenience of a capsule. For more information or to buy any of their products, go to https://chrismasterjohnphd.com/ancestral

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In this episode, you will find all of the following and more:

Riboflavin Show Notes

00:37 Introduction

01:46 Three things that I've changed my mind about while doing the research for this podcast

04:24 Cliff notes

14:13 Three stories of riboflavin deficiency

18:05 Signs and symptoms of riboflavin deficiency

21:31 Speculative symptoms of suboptimal riboflavin status

23:49 Chemical properties of riboflavin

27:22 Medical applications: infants with jaundice, eye surgery for keratoconus, and treatment of fungal keratitis

30:38 Chemical structure of riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD)

33:02 Riboflavin's roles in the body: energy metabolism, the antioxidant system, methylation, detoxification, and other nutrient interactions

34:03 Riboflavin's roles in energy metabolism

39:33 How the different macronutrients (carbohydrate, fat, and protein) affect the riboflavin requirement differently

46:05 Riboflavin's role in the antioxidant system

50:12 Riboflavin's roles in the methylation system

52:29 Riboflavin's interactions with other nutrients: vitamin B6, niacin, and iron

55:47 Riboflavin's roles in detoxification

57:44 Other riboflavin-dependent enzymes include NADPH oxidase, monoamine oxidase, and protein disulfide isomerase.

59:31 The physiology of riboflavin absorption

01:02:31 The physiology of riboflavin utilization and the importance of magnesium, ATP, thyroid hormone, adrenal hormones, and protein

01:06:43 The gold standard marker of riboflavin status is the erythrocyte glutathione reductase activity coefficient (EGRAC).

01:12:11 LabCorp's whole blood riboflavin test, normalized to the concentration of blood hemoglobin, is the closest commercially available equivalent to the EGRAC.

01:14:02 Why urinary glutaric acid is not a specific marker of riboflavin status

01:14:54 Measuring riboflavin status should be done after an overnight fast, and biotin does not interfere with the test.

01:15:54 How the RDA for riboflavin was established

01:22:02 How much riboflavin is needed to optimize riboflavin status and maximally suppress the EGRAC?

01:27:25 Why high doses of riboflavin might be beneficial in cases of suboptimal magnesium, energy, thyroid, or adrenal status

01:31:04 Dietary sources of riboflavin

01:36:39 Free riboflavin is found in milk, fortified flours, and many riboflavin supplements.

01:38:55 Riboflavin is destroyed by light.

01:41:16 Riboflavin is produced in the colon, but it is unknown how much this contributes to systemic riboflavin status.

01:43:55 Factors that interfere with riboflavin status and utilization

01:51:02 Genetic defects in riboflavin metabolism and transport

01:53:50 How common is riboflavin deficiency and suboptimal riboflavin status?

01:58:36 Riboflavin supplementation for iron deficiency anemia

02:00:29 The relationship between riboflavin and the MTHFR C677T polymorphism and effects on homocysteine and blood pressure

02:09:32 Riboflavin supplementation and exercise performance

02:14:30 Whether or not riboflavin supplementation could impair adaptations to exercise

02:18:25 Riboflavin supplementation for migraines

02:25:06 Rapid fire questions

02:25:21 Does it matter whether we take free riboflavin or riboflavin 5'-phosphate?

02:26:51 Should riboflavin be taken with food?

02:30:28 How often should you take riboflavin?

02:32:20 Does it matter if you take riboflavin in one dose or divided doses?

02:33:13 Are there any adverse effects of riboflavin supplements?

Access the show notes, transcript, and comments here:

https://chrismasterjohnphd.substack.com/p/058-why-you-should-manage-your-riboflavin

Chris Masterjohn, PhD, is the Founder and Scientific Director of the mitochondria test Mitome.