Talk:Vitamin C

Re: Sections that need to be rewritten -- FatigueTrackerBot (talk) 17:58, October 3, 2019 (EDT)

 * Hi, Thank you for good comments, JenB. I can rewrite some of these sections. I have identified more papers that confirm long repletion time for ascorbic acid. Will work on this the coming weeks. Rgds, FatigueTrackerBot.

Supplementation
Several studies indicates the recovery from Vitamin C depletion will require several months of treatment. Vitamin C concentrations in plasma and circulating cells were studied in young healthy men and women  each of whom were given six to seven different doses of the vitamin in two depletion-repletion studies. Seven healthy men (4A) and fifteen healthy women (4B), all nonsmokers, age 19-27 years were studied as inpatients. To decrease hospitalization time, outpatient subjects prior to admission were instructed to consume a diet containing < 60 mg of vitamin C. When inpatients, throughout hospitalization they consumed a defined diet containing less than 5 mg of vitamin C daily. Deficiencies of other nutrients were prevented by supplementation. When plasma vitamin C concentrations achieved nadir of <10 µM, vitamin C in solution was administered at 15 mg orally in the fasted state twice daily (30 mg total per day) until steady state for the dose was achieved.

Images
Source and license info added for all images. The full image body image below is particularly good - but would be better edited to remove the mouse and move the key higher up. It's public domain so editing is fine. notjusttired (talk) 17:42, September 8, 2019 (EDT)

Blood tests
Low blood concentration of ascorbic acid may lead to lassitude. From.

On blood test procedure: cited from abstract of : "This chapter describes the analysis of ascorbic acid and dehydroascorbic acid in biological samples. The chapter focuses on ascorbate assays because these techniques are substantially more advanced than those for dehydroascorbic acid and most techniques for the latter are based on those of the former. High performance liquid chromatography (HPLC) with electrochemical (EC) detection is the ascorbate assay technique that provides the highest sensitivity, specificity, and accounts for substance interference. The general separation principles of HPLC are utilized to separate ascorbate from other substances. A mobile phase—or the solution for chromatography—is selected that optimizes both separation and detection. Once separation is accomplished, ascorbate is detected by one of two distinct types of EC detectors, amperometric EC detectors, or coulometric detectors. The principle of both detectors is that they pass a voltage across an area. Current generated by the voltage and the components of the mobile phase are measured. Amperometric EC detectors are “flow by” detectors, in which the solution containing ascorbate and the components of the mobile phase for HPLC separation flow around the detector. Coulometric detectors are “flow through” detectors. The mobile phase and ascorbate flow through the detector, which is porous. Coulometric detectors are preferred over amperometric detectors. The chapter concludes with a discussion of the detection of radiolabeled ascorbate and dehydroascorbic acid."

''Delivery of nutrients to the skin. The location of the vitamin C transport proteins SVCT1 and SVCT2 are indicated. Red arrows depict nutrient flow from the blood vessels in the dermis to the epidermal layer. Nutrients delivered by topical application would need to penetrate the barrier formed by the the outer layer of the skin, called the stratum corneum. '' Vitamin C is ingested, absorbed from the intestinal lumen and transported to various peripheral organs with the blood. Finally, vitamin C is excreted in the renal glomeruli and reabsorbed through the tubular systems. Tissue concentrations are dependent on all of these processes.