Thu, Nov-19-15, 06:50
|
 |
Senior Member
Posts: 15,075
|
|
Plan: mostly milkfat
Stats: 190/152.4/154
BF:
Progress: 104%
Location: Ontario
|
|
http://care.diabetesjournals.org/content/37/5/e93.full
Vitamin c can interfere with the accuracy of blood glucose readings, depending on the type of enzyme used in the strips.
Quote:
Self-monitoring of blood glucose (SMBG) is an integral component in the management of diabetes. However, it is important to understand the limitations of SMBG due to presence of interfering substances (1). We present a patient with diabetes and malignancy, who had falsely elevated blood glucose readings following administration of intravenous ascorbic acid (AA).
A 56-year-old woman with type 1 diabetes was diagnosed with metastatic pancreatic neuroendocrine tumor. She administered insulin glargine and insulin aspart before meals. After three cycles of chemotherapy, due to poor response, she decided to stop further traditional therapies. She consulted a naturopath, who started her on intravenous AA at a dose of 75 g twice weekly. Following this, she noted that her SMBG levels were consistently elevated after intravenous AA. She presented to the University of Washington where her SMBG downloads were reviewed. On the days she received intravenous AA infusion, the average blood glucose was 26.9 ± 4.8 mmol/L, compared with an average of 12.36 ± 2.7 mmol/L on other days. She was using glucose oxidase (GOD)−based strips (OneTouch, LifeScan, Inc., Milpitas, CA) for her SMBG. We suspected interference with AA in the measurement of blood glucose using GOD-based strips and recommended that she measure her blood glucose using glucose dehydrogenase-flavin adenine dinucleotide (GDH-FAD)−based strips (Bayer Contour, Tarrytown, NY). She was advised not to change her insulin doses. A written log comparing the two chemistries with the same blood sample confirmed significantly higher glucose levels with the GOD strips. Unfortunately, the patient died before we could download the meter or compare blood results with a hospital laboratory.
|
Looks like vitamin c wasn't raising blood glucose, it was just increasing the enzymatic reaction with glucose used by the strips.
So maybe if you need to test blood glucose on a regular basis while taking high-dose vitamin c, you should make sure you get a meter that uses the right kind of strips.
If the liposomal vitamin c is better absorbed, then it would make sense that this would start to be a problem at a lower dose of vitamin c itself, maybe explaining those anecdotes. Worsening apparent blood glucose might actually just be evidence that the liposomal vitamin c is doing its job of effectively raising vitamin c absorption.
I think the glucose oxidase variety of strips is by far the most common.
Here's a better study, they added vitamin c to blood samples at different combinations, to see the effect of measured levels of glucose.
http://www.ncbi.nlm.nih.gov/pmc/art...f/jdi-4-679.pdf
These are much larger vitamin c levels than usual supplementation--but you can see a clear dose response and then a plateau towards the higher end, I guess there's an enzyme saturation point.
|
Linear Mode
