@singingbones,
no food 12 hours before draw
only water 12 hours before draw
no bone broth or collagen supplements 48 hours
no biotin 72 hours
no heavy exercise before test
lab draw between 7:30 and 9:00am
These are the tightest rules. Some say 8 hour fast, others 24 hours without biotin
Biotin interferes with the lab assay
Food can suppress CTX
CTX is highest in the morning
Vigorous exercise can cause an immediate increase in CTX
It is so good that you are using bone markers