Question: What to do if taking biotin and yet beta-hydroxyisovalerate is elevated.   Well in theory that's a marker of biotin deficiency, but you might have a defect in a biotin-dependent enzyme so you can try 5 milligrams, but if you still have high beta hydroxy isovaleric you need to start looking at a metabolic disorder, providing there are symptoms. You might have a 20% decrease in that enzyme activity.   This Q&A can also be found as part of a much longer episode, here: https://chrismasterjohnphd.com/podcast/2019/02/24/ask-anything-nutrition-feb-17-2019/   If you would like to be part of the next live Ask Me Anything About Nutrition, sign up for the CMJ Masterpass, which includes access to these live Zoom sessions, premium features on all my content, and hundreds of dollars of exclusive discounts. You can sign up with a 10% lifetime discount here: https://chrismasterjohnphd.com/q&a