Proline and Hydroxyproline Excretion and Vitamin C Status in Elderly Human Subjects

Abstract

1. Plasma and buffy-coat vitamin C, urinary proline, hydroxyproline, creatinine and total amino acid concentrations were meausred in 23 healthy elderly subjects at intervals of 3 months. 2. There was a strong positive correlation between plasma vitamin C and buffy-coat vititamin C. 3. There were not significant correlations between plasma or buffy-coat vitamin CPAMIN C. 3. There were not significant correlations between plasma or buffy-coat vitamin C and total urinary hydroxyproline, whether expressed on a creatinine basis or on a total amino acid basis. Similarly, no significant correlations could be detected involving the proline/hydroxyproline ratio in urine hydrolysates. 4. There was a significant negative correlation between plasma or buffy-coat vitamin C and total urinary proline, when expressed per unit of total urinary proline, when expressed per unit of total urinary proline, when expressed per unit of total amino acids in the hydrolysates. This correlation was not observed with unhydrolysed urine, and it appeared to reside in the diffusible fraction, part of whose proline could be liberated by prolidase digestion. In addition, in the man, there was some evidence for a positive correlation between plasma or buffy-coat vitamin C and the ratio of total urinary amino acids to creatinine. 5. These results support the view that poor vitamin C status in elderly humans may be associated with a defect in collagen proline hydroxylation, reflected by increased excretion of proline-rich, collagen-derived peptides. If this interpretation is correct, it indicates a potential defect in connective tissue repair, and could form the basis of a functional test for subclinical vitamin C deficiency.

Nutritional status of schoolgirls in Isfahan, Iran: Urine composition

“…However, the present results are consistent with the lower weights of the Dastgerd children, and suggest that their growth rate may be less than the University children. The difference in hydroxyproline index is not apparently related to vitamin C status, because no correlation was found between the two, either in these results (r=0.l3) or in those of Bates (1977), even though vitamin C is needed for production of hydroxyproline in collagen.…”

Hypoxemia and hypercapnia: Its relation to joint diseases and the natural treatments for some joint diseases: A review

“…80,81 Vitamin E has the ability of stimulate the formation of new cartilage components, inhibit the breakdown of cartilages, and the administration of 600 IU showed significant benefits. 82,83 Vitamin C is like vitamin E, protects and enhances cartilages formation [83,84,85] . The administration of a little amount (12.5 mg) of Pantothenic acid is effective in relieving symptoms of Osteoarthritis [86,87] .…”

Emerging Evidence on Neutrophil Motility Supporting Its Usefulness to Define Vitamin C Intake Requirements

“…The same applies to measuring DNA oxidation as an indicator of DNA damage [63]. Collagen turnover measured as hydroxyproline excretion was another potential candidate [65]. Unfortunately, the high inter- and intra-individual variation in the response to varying vitamin C intakes reduces its usefulness as a biomarker to define intake recommendations [66].…”