How to Test for Functional Vitamin B12 Deficiency

NutritionFacts .org
NutritionFacts .org
20 Sep 2020

Many doctors mistakenly rely on serum B12 levels in the blood to test for vitamin B12 deficiency.

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Now if you do get your homocysteine tested and despite both B12 supplementation and eating beans and greens it’s still too high (meaning double digits), I have a suggestion, as covered in the final two videos in this video series: Should Vegetarians Take Creatine to Normalize Homocysteine? ( and The Efficacy and Safety of Creatine for High Homocysteine (

How did we end up here? Watch the full series if you haven’t yet:
• What to Eat for Stroke Prevention (
• What Not to Eat for Stroke Prevention (
• Do Vegetarians Really Have Higher Stroke Risk? (
• Vegetarians and Stroke Risk Factors—Vitamin D? (
• Vegetarians and Stroke Risk Factors—Omega 3s? (
• Vegetarians and Stroke Risk Factors—Vegan Junk Food? (
• Vegetarians and Stroke Risk Factors—Saturated Fat? (
• Vegetarians and Stroke Risk Factors—Animal Protein? (
• Vegetarians and Stroke Risk Factors—Vitamin B12 & Homocysteine? (
• How to Test for Functional Vitamin B12 Deficiency (

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Thanks for watching. I hope you’ll join in the evidence-based nutrition revolution!
-Michael Greger, MD FACLM

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