FreeStyle Libre, Vitamin C & Aspirin

[Rachox]

I have toyed with the idea of having an occasional Libre since I became aware of their existence (shortly after my type 2 diagnosis), but with my nearest Asda pharmacy being 15 miles away I don’t have a cheap option. However during my Googling yesterday I found this. Are Libre users generally aware of this? Does taking either of these meds really have much of an impact? I have taken Vitamin C with zinc for years and swear by it to help prevent colds, before taking it I was always getting colds, but since taking Vit C with zinc I rarely get one. I’d be interested in people’s views on these potential interactions. TIA.

 

[Fndwheelie]

I’m on daily ascorbic acid, and I’ve notice most of my sensors read lower than finger pricks tbh.

 

[Bluetit1802]

I'm not on any of those things but my sensors vary from reading low to reading high when checked against my finger pricks.

The only thing that has affected mine is unusually hot weather such as we had in July. The week of the heatwave I saw much higher readings. The following week when it had cooled down (same sensor) it was back to normal. I put it down to the reader being too hot rather than the sensor playing up.

 

[Brunneria]

Yes, I have known about this since I first scoured the Libre website for info before I bought my first sensor.

I supplement an RDA amount of vit C daily, but never go near the huge doses of Ascorbic Acid supplementation that some people choose to take.
My sensors have consistently read approx 1mmol/l below my prick tests for the last 3 or 4 years.
So my speculation would be that large doses of Vit C may affect sensor readings, but since I don't take large doses, they don't have that effect for me.

Although as I am writing this I am kind of speculating whether to do an n=1 test with my next sensor, and see if I could raise my Vit C intake enough to bring the sensor reading into line with my prick tests... yeah, not worth the phaff, but it might be fun to do for a day or two, out of curiosity.

 

[Goonergal]

I don't take either of those, so can't help on that front. From my experience, the sensors are usually a bit wonky for the first day or so (sometimes a bit high, sometimes a bit low), but that evens out to be broadly in line with finger prick tests.

However, it's not the exact numbers that are important if dietary management is your strategy, rather the overall patterns that show what happens between what would be your normal finger prick tests. That's where the learning happens - to see unexpected spikes/lows; double peaks; what happens in the morning; during exercise etc. Whether the actual readings are a point low or high is immaterial if you're not needing to make insulin dosing decisions.

 

[Rachox]

Although as I am writing this I am kind of speculating whether to do an n=1 test with my next sensor, and see if I could raise my Vit C intake enough to bring the sensor reading into line with my prick tests... yeah, not worth the phaff, but it might be fun to do for a day or two, out of curiosity

Don’t do any experiments on my account. I just take the RDA of Vitamin C too. So would drinking the equivalent amount of vitamin C in orange juice (not something I’d entertain these days!) affect the Libre too I wonder?

 

[Rachox]

However, it's not the exact numbers that are important if dietary management is your strategy, rather the overall patterns that show what happens between what would be your normal finger prick tests. That's where the learning happens - to see unexpected spikes/lows; double peaks; what happens in the morning; during exercise etc. Whether the actual readings are a point low or high is immaterial if you're not needing to make insulin dosing decisions.

Oh I agree absolutely, I guess as long as I was consistent with taking the Vitamin C I would get consistently distorted readings (if they are distorted at all!) so would still be able to watch for trends. I was just interested in how much of a difference anyone had noticed in reality if indeed anyone had noticed at all.

 

[Guzzler]

Both vitC and glucose use the same pathway (GLUT1). In the presence of too high a level of glucose vitamin C loses out.
Lowering the amount of carb in your diet so lowering the bg gives VitC improved absorption rate.