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Blood Chemistry

Is serum a good way to measure selenium as mentioned in week 37 re: baseline testing before supplementation?

Chris Kresser:  Serum is okay for selenium. Actually toenail selenium is the best marker for selenium status. Hair selenium is...

What new tests have you included in your standard blood panel since the slide in Week 30 blood chemistry basics?

Chris Kresser:  I’m not sure. I’m just going by memory. I’m not sure if anything new has been added. PTH,...

What should I consider if a patient has low total cortisol but normal free cortisol? So her levels are 2,226 for the total range, and the lower limit of normal total cortisol is 2,750. And for free, 105 for free cortisol, with the range being 80 to 185. So she has high-normal cortisone, symptoms of fatigue in the morning, but her diurnal rhythm is essentially normal. Melatonin is low normal, DHEA was high, let’s see, and then she goes and lists the hormone values. Periods are irregular, 37 and she’s been off birth control the past six months.

Dr. Amy Nett:  So, I mean, the big question is, I think, what are her symptoms? So what are you...

A patient serum magnesium level came back at 2.4, but she’s not taking any magnesium-containing supplements. Are there other explanations for high magnesium level? Is there a normal upper limit? Can too much magnesium cause health problems?

Dr. Amy Nett:  Yeah, so absolutely. If you see high magnesium, a normal magnesium range, even from a conventional lab...

Regarding the standard blood panel that we do, do we run a standard urinalysis on new patients through LabCorp as part of that case review panel?

Dr. Amy Nett:  So, great question. We actually used to. So when I first started working with Chris, we did...

What blood work panels do you recommend for the initial evaluation?

Dr. Amy Nett:  So we do the comprehensive blood panel, which we’re sort of going through all of those markers...

What is being measured for copper and zinc serum?

Dr. Amy Nett:  So copper and zinc in the serum, what you’re measuring there is the level of those minerals...

I’m confused on week 37, part 4 teaching on reverse T3, so rT3-to-T3 ratio. So the rT3 ratio. Chris quotes that the optimal ratio should be above 20 if using free T3 and above 10 with total T3. I’m confused because I would think that you would want the ratio to be low rather than high.

Dr. Amy Nett:  So the ratio, the way you calculate it is the total T3 or free T3 to reverse...

There is a question about the connection between MMA and creatinine and she said that it seems that, I think this was regarding some of the content in the blood chemistry, she said it seems that there is a connection between serum creatinine and MMA.

Dr. Amy Nett: Neither Chris and I are certain about a relationship between blood levels of MMA and creatinine. So...

Question on the pros and cons of the HDRI functional methylation profile versus the Doctor’s Data profile.

Dr. Amy Nett: The HDRI methylation profile actually has a lot more markers than the Doctor’s Data. Doctor’s Data basically...