Prevalence of osteopenia among sedentary young women.

The purpose of this study was evaluating prevalence of osteopenia in young women.40 young untrained women between the age of 20-25 years (obese n = 20, BMI > 30 and thin n = 20, BMI < 20) volunteered to participate in this study. Bone mass density (BMD), percentage body fat and lean mass (g/cm2) were measured with the dual X-ray absorptiometry scans (DEXA). Student's t-test was used for determining the amount of bone normalizing among subjects. The study finding showed that 20% of obese and 65% of thin women had osteopenia and thin groups 3.2% more than obese groups were at risk of bone loss. These findings will help educate the medical community and the public about the importance of prevention--targeting young women who are at risk while they still have time to change their habits and improve their bone health.

The clinical effects of vitamin C supplementation in elderly hospitalised patients with acute respiratory infections.

A randomised double-blind trial involving vitamin C/placebo supplementation was conducted on 57 elderly patients admitted to hospital with acute respiratory infections (bronchitis and bronchopneumonia). Patients were assessed clinically and biochemically on admission and again at 2 and 4 weeks after admission having received either 200 mg vitamin C per day, or placebo. This relatively modest oral dose led to a significant increase in plasma and white cell vitamin C concentration even in the presence of acute respiratory infection. Using a clinical scoring system based on major symptoms of the respiratory condition, patients supplemented with the vitamin fared significantly better than those on placebo. This was particularly the case for those commencing the trial most severely ill, many of whom had very low plasma and white cell vitamin C concentrations on admission. Various mechanisms by which vitamin C could assist this type of patient are discussed.

Uptake and utilization of DL-5-[methyl-14C] tetrahydropteroylmonoglutamate by cultured cytotrophoblasts associated with neural tube defects.

A significant advance in the primary prevention of neural tube defects (NTD) is the recent finding that the periconceptional supplementation with folate has a 72% preventive effect against recurrence of NTD. However, failure of folate supplements to prevent all recurrences supports the multifactorial causation hypothesis, with inherited components exerting their influence, possibly through defects of storage, transport, or metabolism of folate. We have assessed the kinetics of DL-5-[methyl-14C]tetrahydropteroylmonoglutamate ([14C]MTHF) uptake and incorporation into the nucleic acid and protein pools by NTD-associated and control trophoblasts cultured in a medium lacking thymidine and other DNA precursors. We report a significant initial "lag" in the rate of incorporation of 14C label into the nucleic acid pool in NTD-associated trophoblasts. This we attribute to a defect in the de novo pathway of folate metabolism and its associated pathways, including the pathway for methionine synthesis, although the rate of incorporation of 14C label into the protein pool was not significantly different from that of the control cells. We discuss the possible pathways involved in the transfer of the label from the methyl group of [14C]MTHF to the nucleic acid pool, and argue that a slightly (but significantly) reduced rate of uptake into the NTD-associated cells is a reflection of the lag in incorporation into the nucleic acid pool. It is concluded that in the absence of thymidine, most of the NTD-associated trophoblasts require a longer period than controls to adjust to utilization of [14C]MTHF for synthesis of DNA, a period that could be crucial for completion of neural tube embryogenesis. We suggest that these findings could offer a way to a marker for risk of NTD.

Blood vitamin C concentrations in patients with diabetes mellitus.

Plasma and buffy layer vitamin C concentrations have been measured in insulin dependent and non-insulin dependent diabetic patients and the results compared with age and gender matched non-diabetic controls. No differences were found between the controls and the diabetics nor between the different types of diabetes, although patients who had had clinical diabetes for longer had higher plasma vitamin C values than patients in whom the disease was not long standing. There were no significant changes in the distribution of vitamin C between plasma and white cells in the diabetic nor in patients with marked hyperglycaemia. We conclude that the vitamin C intakes of the majority of diabetic patients we studied, who are probably typical of diabetics receiving hospital treatment in the United Kingdom, are adequate and are sufficient to maintain satisfactory plasma and buffy layer vitamin C concentrations. These findings are discussed in the light of reports which have shown lower levels of vitamin C in the blood of diabetic patients and competition between vitamin C and glucose for transport across the cell membrane.

Changes in plasma and buffy layer vitamin C concentrations following major surgery: what do they reflect?

Plasma and buffy layer vitamin C concentrations have been measured in 19 patients before and following major surgery, and falls of 36% and 43% respectively were recorded on the first post-operative day. However, the change in the buffy layer could not be accounted for by a change in the concentration of vitamin C in platelets, mononuclear cells or polymorphonuclear leucocytes, the cell types which form the buffy layer. The buffy layer change could be explained by a post-surgical increase in the number of polymorphonuclear leucocytes which, when the buffy layer vitamin C is expressed per 10(8) white cells, dilutes the platelet and mononuclear cell contribution to the buffy layer vitamin C concentration. The fall in buffy layer vitamin C does not, therefore, reflect any increased demand for white cell vitamin C in the immediate post-operative period, although the decrease in plasma vitamin C could imply some increased utilisation or redistribution of the non-cellular compartment.

The effects of maternal folic acid and vitamin C nutrition in early pregnancy on reproductive performance in the guinea-pig.

1. The effect of different intakes of folic acid (FA) and vitamin C on pregnancy in the Dunkin-Hartley guinea-pig was examined. Female guinea-pigs were subjected to three graded intakes of FA and vitamin C ('deficient', 'intermediate' similar to recommended daily intakes (RDI), and 'supplemented') during early gestation and up to the time of neural tube closure (17th day of gestation), and then returned to the RDI of these vitamins. 2. Plasma and blood cell concentrations of these vitamins were measured once before and at the end of the dietary treatments. Reproductive performance was assessed in terms of the number of resorbed and aborted embryos and weight and size of the live fetuses on the 36th day of gestation. 3. The short-term deficiency of either of these two vitamins, insufficient to affect maternal health, had a dramatic effect on the reproductive performance. 4. The RDI of FA was significantly less effective than the supplemented intake in preventing embryonic deaths. The RDI of vitamin C produced lighter and smaller live fetuses than the supplemented intake. 5. The implications of these findings with regard to vitamin status in early pregnancy in man are discussed.

The cause and correction of low blood vitamin C concentrations in the elderly.

Chronically sick elderly women had low intakes and low blood concentrations of vitamin C. Small dietary supplements of vitamin C increased the concentration of vitamin C in their plasma and leucocytes to those found in both the active elderly and the young. These findings confirm that low concentrations of vitamin C in the institutionalized and chronically sick elderly are primarily due to poor intake and can be easily corrected by dietary changes. The case for increasing the intake of vitamin C in these patients is discussed.

Plasma levels of vitamin C components in normal and diabetic subjects.

Recent reports of high dehydroascorbic acid levels in Asian subjects suffering from diabetes mellitus have led us to examine plasma dehydroascorbic acid levels in diabetic and non-diabetic Europeans. We can find no evidence that diabetic patients have higher plasma dehydroascorbic acid levels than nondiabetics, and consider some possible reasons for the discrepancy between this finding and those of earlier reports.