Misses ascorbate role in production of collagen, and this is
likely more of an issue that oxidative stress.
http://care.diabetesjournals.org/content/diacare/27/10/2491.full.pdf Diabetes Care, Vol. 27, Oct. 2004
Lymphocyte and Plasma Vitamin
C Levels in Type 2 Diabetic
Patients With and Without Diabetes Complications
Diabetes has been considered to be associated with oxidative
stress. It has been suggested that increased free radicals and decline of
antioxidant defense mechanisms induce diabetic micro- and macrovascular
complications (1–3). Vitamin C is one of the major antioxidants and is detected
in various blood components (4). However, measurements of vitamin C levels have
shown inconsistent results, and the interpretation of vitamin C levels in
diabetes as an antioxidant biomarker has not been clarified (5–8). In this
study, we investigated the lymphocyte and plasma vitamin C levels in type 2
diabetic patients with and without diabetes complications.
Increased oxidative stress in diabetes could contribute to depletion of antioxidants
such as vitamin C (2,3). In this report, we demonstrated that the lymphocyte
vitamin C level is significantly lower in type 2 diabetic patients, but we
could not observe such an association in plasma vitamin C levels. The plasma
concentration of vitamin C is considered to be strongly correlated with
transient consumption of foods such as fruit, supplements, and vegetables (4).
lymphocyte vitamin C level in diabetic patients was significantly lower than in
control subjects (18 4.5 vs. 28 7.9
nmol/mg protein, P
0.0001), whereas the
plasma vitamin C level was not different (59 19 vs. 53 18 mol/l, P 0.17) (Fig. 1A and B). There were
no significant linear correlations between the lymphocyte and plasma vitamin C
levels in diabetic patients (r 0.011, P 0.95) as well as in control subjects (r
0.14, P 0.35). The lymphocyte vitamin C level in diabetic patients with
complications was significantly lower than in those without complications (17 3.3
vs. 21 5.4 nmol/mg protein, P 0.011) (Fig. 1C),
whereas the plasma vitamin C level was not different (59 18 vs. 59 21 mol/l, P 0.97). CONCL
Testing for levels [Laboratory testing reflects recent dietary
intake, not storage--jk].
tests use dichlorophenolindophenol, a redox indicator,
to measure the levels of vitamin C in the urine and in serum or blood plasma.
However these reflect recent dietary intake rather than the level of
vitamin C in body stores. Reverse
phase high performance liquid
chromatography is used for determining the storage levels of
vitamin C within lymphocytes and tissue.
It has been observed that while serum or blood plasma levels follow the circadian rhythm or
short term dietary changes, those within tissues themselves are more stable and
give a better view of the availability of ascorbate within the organism.
However, very few hospital laboratories are adequately equipped and trained
to carry out such detailed analyses, and require samples to be analyzed in
specialized laboratories. https://en.wikipedia.org/wiki/Vitamin_C#Deficiency