I have not been able to find much information beyond what tests are normally done with Capillary puncture sampling, as opposed to what tests are possible.

Could we test for a single micronutrient, or maybe some subset of nutrients with the blood drawn in this way? Is the issue purely volume, or are there other factors?


  • $\begingroup$ Welcome to Biology! What exactly do you mean with micronutrient? An example would be best, as trace elements may have very different detection limits than vitamins. $\endgroup$
    – AliceD
    Mar 25, 2015 at 2:06
  • $\begingroup$ Thanks :) And by micronutrient, I was referring to any nutrient you would see on a nutrition label (yes, I know that's broad). Is there a good resource/chart that has micronutrient specific-info on testing methods / requirements? Or even just a good place to look for that kind of thing (I can do the research, as soon I can find a good place to look :) ). $\endgroup$ Mar 26, 2015 at 18:15

1 Answer 1


Detection methods are constantly getting better, requiring lesser amounts of blood to make a determination. In newborns, a heel blood sample (of capillary blood) is used to detect up to 40 (sometimes more) disorders from maple-sugar urine disease and hypothyroidism to hemoglobinopathies and organic acid conditions. If such large molecules can be detected in capillary blood, smaller molecules should as well.

There are differences in central venous sampling and capillary blood sampling, but it could be argued that since the capillaries are the site of exchange of nutrients, this is the most accurate site to determine availability of micronutrients in blood.

One reason labs take more blood than required for the test is to run a second analysis if the first is abnormal. Although it's not done for every abnormal, clinicians often want to confirm significant abnormals before treating a possible lab error.

Newborn screening tests
Newborn Screening
Conditions Screened By State
A Layperson's Guide to Tandem Mass Spectrometry

  • $\begingroup$ Hey thanks for the answer and links! Would love to dig more into the specifics on the differences between central venous sampling and capillary blood sampling, re: nutrients and blood content -- any resources you could recommend? $\endgroup$ Mar 26, 2015 at 18:19
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    $\begingroup$ @mattmattmatt - Gosh... I started learning about that, um... in 1977. Google scholar using the words "arterial, venous, capillary blood X" should help! :) $\endgroup$ Mar 26, 2015 at 18:26

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