Bioavailability of Vitamin C

[ofonorow]

Then by all means, please keep posting the graphs! Thank you.

For the next experiments, I want to keep all conditions the same as the IV baseline. (Per water discussion, we know a) the meter can read vitamin C without glucose, and b) I did discover that even having a cup of coffee about an hour later had no effect on the 165 mg/dl reading afterwards.)

After these experiments, I am willing to investigate whether taking Lantus changes the readings. And I do want to try the 2 to 4 hours out investigations, especially with liposomal. (Although that is a long time without coffee in the morning!)

Added - just noticed the post previous to your last post johnwen. And the thought occurs that the reason for the 2 to 4 hour spike may not be related to the kidney, rather the oral vitamin C that is traveling down the intestines - and finally reaches the blood stream. (From a Levy book I learned that generally carbs leave the stomach in 2 hours, proteins in 4 hours and fats in 6 hours.)

[ofonorow]

Measurements of 10 gram UltraFINE ascorbic acid powder in one gulp (4 oz of water).

Due to some stress, I consider these numbers a practice or dry run as my own cortisol may have spiked! (One meter (b) read over 400 during the baseline, so we switched to a new meter, so B in the previous reading is new). My initial baselines were about 10 points higher than last week, we started earlier (didn't have to drive to doctors). Even if not perfect, the numbers do illustrate that if you are not looking early (first minute!?) you miss a lot of the action from taking ascorbic acid by mouth.

Code: Select all

Baselines
A.    134 mg/dl
B.    140 mg/dl  (new B)   after old meter > 400
C     135  mg/dl

Minute 0 - gulped 10 grams ascorbic acid in 4 oz water.

Code: Select all

Meter             Minute               Reading

A                    +1                  247
   B+               +2                         304
       C             +3                                 163
A                    +4                 147
   B+               +5                         259
        C            +6                                 280
A                    +7                  202
   B+               +8                         215
       C             +9                                255
 A                  +10                  207
    B+             +11                        170
       C            +12                               169
 A                  +13                164
   B+              +14                       140
      C             +15                              142
 A                  +16                159
   B+              +17                        157
       C            +18                              200
A                    +19               196
   B+               +20                      167
       C             +21                            188
A                    +22                145
   B+               +23                       149
       C             +24                             152
A                    +25                141
   B+               +26                       145
       C             +27                             156
A                    +28                146
   B+               +29                        148
       C             +30                               140
A                    +31                 176
   B+               +32                         160
       C             +33                                140
A                    +34                  161
   B+               +35                          185
       C             +36                                 147
A                    +37                 147
   B+               +38                          150
       C             +39                                  142
A                    +40                159
   B+               +41                          143

Paused measurements

       
A                    +45                 145
 
   B+               +50                  142

Notes: Remember this is not a slow IV drip into the vein, there are probably multiple pathways for ascorbate to enter the blood stream, which may explain some of the small spikes.

But the question remains - how in the heck does so much reach the blood stream in the first minute!

Part of the plan is to compute the deltas from baseline for 40 minutes - IV and oral - and add them up as a simple comparison of bioavailability.

[Johnwen]

Resized this one hope it's not to big!
We'll see





Fixed after Owen spotted lost figure!

answer:
http://www.livestrong.com/article/55439 ... od-sugars/

[ofonorow]

That was quick johnwen! Thank you. (Added the old chart so we can see them together.) Sort of opposite tracks as you might expect. And I wonder if there is some kind of insulin response for the rapid decline in the oral measurements.

My first thought was to measure the delta between the baseline (or better, the last measurement) - which seems show how much vitamin C entered the blood. But this is more difficult in the oral case, because not all may get into the blood stream right away, so there is both an into the blood flow and out flow? at the same time.

Added - didn't check all numbers but noticed the 304 (B+) for minute 2 was missing.

More - some other observations.

Peak of the IV when the 10 grams ran out of the bag was 210 (or 90 above) baseline. Rate approximately 22.5 point increase every 10 minutes if the IV had been continued. So next gram (4 minutes) in bag should have reached oral peak.

Oral immediately reached 233 (average of first six measurements). One could argue for the amount up to 10 grams, that oral is more bioavailable than IV - up to probably 11 grams.

In theory, if a larger IV increases at the same rate, then 50 gram (or 200 gram) IV/Cs should raise the blood levels to the heights that some researchers report - over time

And 10 grams is probably close to the max one-time oral intake. (However, we may be seeing why a 8-10 gram dose, every 20 minutes, for 2 hours, cures the common cold

[Johnwen]

Here I combined the Oral & IV graphs together. It got kind of crowded so I Thickened the IV Lines for contrast!!





This is a comparison of Oral & IV on Meter A




This is a comparison of Oral & IV on Meter B



This is a comparison of Oral & IV on Meter C





Just having Fun on a rainy Saturday!

[pamojja]

Just having Fun on a rainy Saturday!

Also interesting area under the curve!

[ofonorow]

Thank you johnwen. Very nice. We may be close to being able to rest our case

Me thinks we have illustrated the point that oral ascorbic acid makes it into the blood stream, in my case, without much loss compared with IV/C.

And we have shown that any measurements of oral vitamin C which ignored the first fifteen minutes would have missed all this action.

And again, other than possibly the Hickey/Roberts "weak acid through the stomach wall" explanation, we are at a loss to explain how in one minute, so much"glucose" (vitamin C) is detected in the fingers!?

Have to reorder more test strips, so we have time to consider the next experiment...

1) 250 mg orally every minute experiment for the direct comparison with IV/C.

2) For completeness, 11.3 grams of sodium ascorbate orally. Might as well gulp because if previous experiments were valid, this will be a much lower curve (more like time release)

3) We have never measured liposomal in the blood this way, but the reason is probably that we didn't wait long enough.. (3 or 4 hours without coffee doesn't sound like fun though.)

4) Not sure I want to take 10 grams of sugar (or glucose) all at once, but I am curious if the blood sugar would spike in the first 10 minutes like the vitamin C did? If so, we could speculate that glucose/ascorbate share the same pathway quickly into the blood stream.

And here is a conversion of the numbers from mg/dl to umol/l - to compare the numbers with recent studies and Hickey.

From this wiki (and a check of the numbers given the atomic weight of ascorbic acid (C6H8O6) with a molar mass of 176.12) the kidney threshold I am familiar with is 1.5 mg/dl which is 85 umol/l. See vitamin C (ascorbic acid) down the pagehttps://en.wikipedia.org/wiki/Reference_ranges_for_blood_tests The conversion factor for ascorbic acid is 56.78, so you multiply the mg/dl by 56.78 to get the umol/l number. Checking 1.5 mg/dl * 56.78 = 85.17 umol/l

The highest IV was 210 mg/dl 11,923.800000000001 umol/l
The highest oral was 304 mg/dl 17,261.12 umol/l

The problem is the glucose reader thinks its measuring glucose with a molar mass of 180.16, so the actual numbers are a few percent less.

And we need to deduct the glucose (approximately 130 mg/dl) for the vitamin C part... later

Here is a web conversion tool. http://www.endmemo.com/medical/unitconvert/Vitamin_C.php with a batch mode..

For the record, here is the conversion of the first 40 minutes of raw IV data.

Code: Select all

147,143,143,152,146,152,159,150,162,159,164,159,168,164,174,162,167,173,179,174,178,175,187,189,187,199,191,211,207,200,207,198,210,210,199,200,197,191,194,184

8346.66
8119.54
8119.54
8630.56
8289.880000000001
8630.56
9028.02
8517
9198.36
9028.02
9311.92
9028.02
9539.04
9311.92
9879.72
9198.36
9482.26
9822.94
10163.62
9879.72
10106.84
9936.5
10617.86
10731.42
10617.86
11299.22
10844.98
11980.58
11753.460000000001
11356
11753.460000000001
11242.44
11923.800000000001
11923.800000000001
11299.22
11356
11185.66
10844.98
11015.32
10447.52

here is the conversion of the first 40 minutes of oral data.

Code: Select all

247,304,163,147,259,280,202,215,255,207,170,169,164,140,142,159,157,200,196,167,188,145,149,152,141,145,156,146,148,140,176,160,140,161,185,147,147,150,142,159

14024.66
17261.12
9255.14
8346.66
14706.02
15898.4
11469.56
12207.7
14478.9
11753.460000000001
9652.6
9595.82
9311.92
7949.2
8062.76
9028.02
8914.460000000001
11356
11128.880000000001
9482.26
10674.64
8233.1
8460.22
8630.56
8005.9800000000005
8233.1
8857.68
8289.880000000001
8403.44
7949.2
9993.28
9084.8
7949.2
9141.58
10504.300000000001
8346.66
8346.66
8517
8062.76
9028.02

And finally for my last trick, lets look at the vitamin C portion of the highest measurements

Code: Select all

IV/C   210  -  124 (glucose baseline) =  86 mg/dl    ==>   approximately   4,883.08  umol/l
Oral   304  -   134 (glucose baseline) =   170 mg/dl   ==>   approximately   9,652.6   umol/l

What did the NIH say was the highest oral concentration achievable

Added, this from Hickey
Pharmacokinetics of Oral Vitamin C
http://www.livonlabs.com/proof/Dr_Hickey_Clinical_Study_Published.pdf

Of the 15 000 measurements, the highest recorded serum value in a subject not receiving intravenous vitamin C was 220 umol/L . This is consistent with the published maximum value. With intravenous administration, Biolab have recorded plasma values in excess of 5000 umol/l, in subjects under ascorbate treatment for osteosarcoma

[Johnwen]

OWEN WROTE:
4) Not sure I want to take 10 grams of sugar (or glucose) all at once, but I am curious if the blood sugar would spike in the first 10 minutes like the vitamin C did? If so, we could speculate that glucose/ascorbate share the same pathway quickly into the blood stream.

I was curious about the same thing.
If you did a glucose tolerance test and then compare your V-C Readings with what these readings give you!

Here's a part of a flyer that is given to patients who are being checked this way.
I took out all the other things about How long and what to do prior and just copied the juicy stuff!

This is what the Glucose Tolerance Test measures.
FIRST, We take a "baseline" glucose reading.
THEN, you are asked to drink a liquid of pure glucose and water,
Then, We take more glucose readings over the next 1-4 hours.

These readings allows us to draw a GRAPH, showing your body's response to glucose.
In ALL cases, you body will show a sudden "spike" in the blood sugar level almost immediately after you drink the fluid.
That spike must drop down to normal (less than 120) after about three hours.

If the blood sugar level drops to less than 120, then you are OK - NOT diabetic.
If the reading goes high and STAY high (more than 150) after three hours,
then you are diabetic, and need to start treatment IMMEDIATELY.

I agree about the Dosing the liquids used for these tests come in 50,75 and 100 GRAM. Which in your situation may cause a reactive reaction. So to be on the safe side. I think using the same dosing as the V-C which you said was 10 grams in 4oz. Of water.
However don't use table sugar which is sucrose. Use glucose or fructose which I've seen at health food stores for a not to bad prices!
Glucose and fructose is pretty much like V-C chemically and will give better examples.

Ascorbic Acid | C6H8O6
Table sugar (sucrose) is C12H22O11
Glucose and fructose C6H12O6

I'd for one would be interested in the results of this test, it would also prove if your formulations pan out!!

[ofonorow]

Good idea on the glucose (only) 10 grams johnwen. But will probably do glucose last as each test is probably $40 in test strips

I shared your combined graph with Dr. Hickey and this was his early response:

Hi Owen,

It would be very interesting indeed if a proportion of vit C is absorbed quickly.

The first question you are likely to be asked is: how have you calibrated the measuring device?

This may be me asking granny to suck eggs but I have experience of specialist labs badly messing up vitamin C measurements...

Do you have a response curve for ascorbic acid in distilled water?
Do you have a response curve for glucose in distilled water?
Then you need response??
s obtained by adding ascorbic acid to different physiological concentrations of glucose.

You may have all of these but I am particularly short of time for the next few days and unable to search through your forum properly.

Note in the discussion of pharmacokinetics to always remember Cathcart's bowel tolerance.
The dominant data is for healthy individuals and the experimenters ignore Cathcart.
Ignoring bowel tolerance is nuts but there are (of course) political and financial reasons for the data being restricted in this way.

Keep experimenting

Steve

[OxC]

The first question you are likely to be asked is: how have you calibrated the measuring device?
Do you have a response curve for ascorbic acid in distilled water?
Do you have a response curve for glucose in distilled water?
Then you need responses obtained by adding ascorbic acid to different physiological concentrations of glucose.

I agree that calibration of the meter is crucial for interpreting your data. However, the suggestion for testing against solutions made in distilled water is not the way to do it, since it ignores the effects of the sample matrix (whole blood). In clinical assays, differences in the measured response due to the sample matrix are referred to as 'matrix effects' and they can be tremendously large, depending on the design of the assay system. Your meter uses an enzyme system (GDH-FAD) coupled with a coulometric measurement method (i.e., it actually measures a flow of electrical current through the fluid absorbed into the test strip), so you can assume that the pH of the solution being tested could enormously influence its response. For example, whole blood can be expected to always be in a very narrow pH range around 7.4. Because blood has a huge buffering capacity, you could add a significant amount of ascorbic acid without altering the pH very much. But, even adding a very small amount of AA to pure water shifts the pH a lot'5 mg/dL of AA in pure water will give a solution of pH 3.9. The other components of blood, including the RBCs, proteins, and salt content, all have huge potential to affect either the enzyme reaction or the coulometric measurements. You cannot expect measurements done on substances in pure water to reflect the response of the meter when measuring the same substance in whole blood.

This link describes information the manufacturer of your meter submitted to the FDA. You will see several useful things here. First, that the method can use whole blood that is anticoagulated with EDTA or heparin. Second, that the way to properly test response to interfering substances is to spike whole blood with the interfering substance, and then test that blood with the meter. Finally, you will see that the manufacturer claims that the interference from ascorbate is not significant at concentrations up to 5 mg/dL.

So here's how I suggest you calibrate your meter:

• Obtain at least 10 mL fresh whole blood anticoagulated with EDTA (purple top tubes) or heparin (green top tubes).
• Reserve 1.0 mL of blood in a small tube labeled '0' (or "baseline").
• Make a solution of AA in water containing 8000 mg/dL (an 8% AA solution).
• Label 7 test tubes as follows: 400, 200, 100, 50, 25, 12.5, and 6.25. Pipet 2.0 mL of blood into the tube labeled 400, and pipet 1.0 mL of blood into the others.
• Add 50 uL of the 8% AA solution to the 2.0 mL of blood in the 400 tube, and mix well. (The spiked amount of AA then represents a sample containing 400 mg/dL AA.)
• Remove 1.0 mL of blood from the 400 tube, and mix it with the 1.0 mL of blood in the 200 tube.
• Remove 1.0 mL of blood from the 200 tube, and mix it with the 1.0 mL of blood in the 100 tube.
• Continue this process (you are performing what is called a serial dilution) until you have 2.0 mL of blood in the tube labeled 6.25
• Test the response of the meter to the blood in all 8 tubes (0 thru 400), and use this data to plot a curve of the response, using the 0 tube result as baseline.

[ofonorow]

Thank you OxC for the professional calibration technique, which I may try if I can obtain the whole blood. (Not sure why the EDTA should be added as this is not the condition in our blood streams?)

At this point, the reason we call these measurements "crude", are because the precise numbers are not material to the argument that ascorbic acid (if it is indeed being measured) enters the blood stream much more rapidly than has been so far reported.

There may be a way to calibrate based on the 10 gram IV/C numbers to help determine the approximate meter readings. (sanity check) 10 grams was infused over 40 minutes, or 2.5 grams every 10 minutes, or 250 mg every minute.

For example, the baseline reading for the IV was 124 mg/dl (assuming 1.5 mg/dl vitamin C)

After 10 minutes the readings were approximately 160 mg/dl - about 35 mg/dl higher after approximately 2.5 grams infused. Final numbers depend on the blood volume

5 liters
In an average healthy adult, the volume of blood is about one-eleventh of the body weight. Most sources state the volume of blood in an average human adult, who is between 150 to 160 pounds, as between 4.7 and 5 liters, although the more recent sources state the volume of blood in an average adult as 4.7 liters

2.5 grams is 2500 mg, so we are adding 2500mg/50 DL (5 liters) which reduces to 50 mg/dl as a rough approximation. (35 mg/dl measured increase versus 50 mg/dl predicted, although I am unfortunately larger than the typical male.)

[OxC]

(Not sure why the EDTA should be added as this is not the condition in our blood streams?)

It's just that whole blood without anticoagulant will clot (coagulate) in about 5 or 10 minutes, so there isn't time to make dilutions and perform the tests before the blood turns into a lump instead of a fluid.

At this point, the reason we call these measurements "crude", are because the precise numbers are not material to the argument that ascorbic acid (if it is indeed being measured) enters the blood stream much more rapidly than has been so far reported.

"...ascorbic acid (if it is indeed being measured)" is one question that this procedure will answer.

[ofonorow]

Measurement #3 - 11.3 grams sodium ascorbate in 4 oz water by mouth (gulp)

Baselines
A 99 mg/dl
B 112 mg/dl
C 112 mg/dl

Time 0 - gulped the 11.3 grams sodium ascorbate.

Code: Select all

Meter                  Time                      Reading
A                          +1                          117
  B                        +2                               116
    C                      +3                                    142
A                          +4                         128
  B                        +5                                140
    C                      +6                                      138
A                          +7                          129
  B                        +8                                 137
    C                      +9                                       113
A                         +10                          134
  B                       +11                                124
    C                     +12                                      128
A                         +13                         131
  B                       +14                                 198         ** felt like a bad reading - meter took too long to report
    C                     +15                                       128
A                         +16                         127
  B                       +17                                 130
    C                     +18                                       145
A                         +19                          135
  B                       +20                                 120
    C                     +21                                        129
A                         +22                           131
  B                       +23                                 127
    C                     +24                                        128
A                         +25                           147
  B                       +26                                 130
    C                     +27                                        120
A                         +28                           123
  B                       +29                                 125
     C                    +30                                        136
A                         +31                           132
  B                       +32                                  129
    C                     +33                                        131
A                         +34                            129
  B                       +35                                  128
    C                     +36                                        138
A                         +37                           132
   B                      +38                                  129
      C                   +39                                         129
A                         +40                           134

Observations.

#1. No matter what we are measuring (my theory is we are measuring ascorbate, rather than glucose, although not necessarily the numbers shown on the meter) this experiment illustrates the difference between the oral consumption of ascorbic acid and sodium ascorbate.

Brings us back to the mystery: Why does so much more ascorbic acid get absorbed into the blood stream so rapidly?

#2 Even sodium ascorbate raises blood levels in the first few minutes.

#3 My guess is that sodium ascorbate absorption generally follows the traditional thinking and has to travel down the gut so that the absorption is spread out over time.

[tjohnson_nb]

Personally, I can feel the effect of ascorbate in the first few minutes after a tsp. It's a sort of increase in energy and more positive outlook. It does seem to be short-lived though I'm sure I still get all the other benefits. That sort of matches your numbers.

[Johnwen]

Ya think??? you can find the answer to your question in this quote??
What does V-C look like Chemically???

THEN, you are asked to drink a liquid of pure glucose and water,
Then, We take more glucose readings over the next 1-4 hours.

These readings allows us to draw a GRAPH, showing your body's response to glucose.
In ALL cases, you body will show a sudden "spike" in the blood sugar level almost immediately after you drink the fluid.