blood levels glutathione Glutathionyl Hemoglobin and Its Emerging Role as a Clinical Biomarker of Chronic Oxidative Stress What is glutathione and why
Description
It looks like the answer is a bit of both

Gastroenterol Clin North Am
Primary Sclerosing Cholangitis

If two formulations are otherwise identical except for B12 form, the methylcobalamin version will be more expensive

Nutrients 8(12): 767
Homocysteine is also known to be elevated in cases of osteoporosis
