1. < Osteoporosis & Bone Health

cannot remember about what to stop taking before blood test

Posted by alexxa @alexxa, Sep 28 5:06pm

Hello,
Can someone refresh my memory about 'stop taking vitamins/supplements containing ....' for at least 2 days prior to a blood test for .... OK was it just P1NP or was it CTX?
Wow, this is definitely not fresh in my mind and I can't find it in my emails or records of information at the moment.
I know it was some kind of supplement and/or vitamin that would interfere with a blood test but I can't recall if that included CTX. Thank you in advance!

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mayblin | @mayblin | Sep 28 6:25pm

I copied and pasted the following from a previous discussion, hope it helps:

"Among the two bone markers, CTX has a very wide reference range, reflecting large variation among different individuals as well within an individual. The influencing factors that are uncontrollable include age, gender, menopausal status, ethnicity, disease and drug, and fracture, etc. The following is a list of factors which can be controlled:
•circadian rhythms
•food intake
•menstrual
•seasonal
•exercise
•life style
Circadian rhythms and food intake plays a big part in daily ebb and flow of CTX. For example, CTX peaks at 01:30-04:30am, and bottoms at 11:00am-03:00pm. Food in the morning could decrease CTX reading as much as ~18%.

To summarize, in order to get a more accurate reading of CTX, it’s best to:
•fast in the morning;
•do an early morning 8-9am testing, or within one hour of waking up if feasible, and be consistent in timing of blood drawing (set an appointment online!);
•stop collagen and biotin supplements 48-72hours before blood drawing;
•refrain from physical activity with high intensity for 24-48 hours. Daily walking should be fine
•stick with a same lab as different assays may be used at different labs

P1NP has very small fluctuations so get it done at the same time of CTX testing should give you a pretty reliable reading."

I usually get them done no later than 8:30am, and consistent between 8-8:30am.

REPLY
1 reply
alexxa | @alexxa | Sep 28 8:06pm
In reply to @mayblin "I copied and pasted the following from a previous discussion, hope it helps: "Among the two..." + (show)
@mayblin

I copied and pasted the following from a previous discussion, hope it helps:

"Among the two bone markers, CTX has a very wide reference range, reflecting large variation among different individuals as well within an individual. The influencing factors that are uncontrollable include age, gender, menopausal status, ethnicity, disease and drug, and fracture, etc. The following is a list of factors which can be controlled:
•circadian rhythms
•food intake
•menstrual
•seasonal
•exercise
•life style
Circadian rhythms and food intake plays a big part in daily ebb and flow of CTX. For example, CTX peaks at 01:30-04:30am, and bottoms at 11:00am-03:00pm. Food in the morning could decrease CTX reading as much as ~18%.

To summarize, in order to get a more accurate reading of CTX, it’s best to:
•fast in the morning;
•do an early morning 8-9am testing, or within one hour of waking up if feasible, and be consistent in timing of blood drawing (set an appointment online!);
•stop collagen and biotin supplements 48-72hours before blood drawing;
•refrain from physical activity with high intensity for 24-48 hours. Daily walking should be fine
•stick with a same lab as different assays may be used at different labs

P1NP has very small fluctuations so get it done at the same time of CTX testing should give you a pretty reliable reading."

I usually get them done no later than 8:30am, and consistent between 8-8:30am.

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Great, I really appreciate this!
Very comprehensive list - hadn't seen all of this before. I do remember now about the biotin and collagen and taking the blood draw as close to 8 a.m. as possible too.

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