Leucocyte Ascorbic Acid Research Articles

Plasma and leukocyte ascorbic acid levels in the elderly

A survey of ascorbic acid blood levels was carried out in the elderly population of a South Wales town. Response rates of 88% for the men and 84% for the women were obtained, and 830 subjects were seen, 93% of whom were living at home. The ascorbic acid concentration was estimated in the plasma and leukocytes (including platelets) and found to decline significantly with advancing age. Mean plasma levels were 0.24 mg/100 ml and 0.37 mg/100 ml in 202 men and 429 women aged 75 years and over; their mean leukocyte levels were 16.6 µg/108 cells and 21.4 µg/108 cells, respectively. These values are considerably lower than those reported from studies of younger persons. Information was obtained about consumption of fresh fruit and green vegetables. Vitamin C blood levels were correlated with both, the effect of the fruit being the stronger. More fruit was eaten by women than by men and more by nonsmokers than by smokers. These differences did not seem to account for the fact that blood ascorbic acid levels were higher in women than in men, and higher in nonsmokers than in smokers. The clinical importance of the low ascorbic acid levels is being investigated by a randomized controlled trial.

Vitamin C metabolism and the common cold.

Male and female university students at the commencement of common cold symptoms were given a single dose of 500 mg of vitamin C. Plasma and leucocyte ascorbic acid concentrations were then measured for six hours. Symptom severity was recorded. The test was repeated twenty-three days after the last symptom had disappeared. The ascorbic acid blood response curve had then returned to normal. Significant and similar elevations of plasma ascorbic acid occurred in both sexes in the cold and post-cold tests. The leucocyte response was significantly reduced in the males but was unaffected in the females in the cold test. The regression coefficients between leucocyte and plasma values (P/L regressions) confirmed that ascorbic acid metabolism was less deranged in females than males during the cold test. Administration of ascorbic acid was associated with increases in blood ascorbic acid concentrations during the post-cold period but not during colds. A single dose of 1000 mg raised blood ascorbic acid concentrations in both sexes during their colds. The elevation was higher, and maintained for two hours longer in the females.In vitro incubation of leucocytes in ascorbic acid confirmed that their ascorbic acid load could be increased by approximately 100% while cold symptoms were present. A significant association between cold symptoms and the state of ascorbic acid metabolism was demonstrated by correlating the ratio of toxic to catarrhal symptoms with P/L regressions during colds. When catarrhal symptoms are severe, ascorbic acid passes from the leucocytes into the plasma, and thence into the inflamed respiratory membranes. When toxic symptoms are relatively more severe, ascorbic acid is retained in the cells. The beneficial effect of vitamin C on the common cold is associated with its influence on ascorbic acid metabolism. A sex-linked difference in ascorbic acid metabolism is manifested during the common cold which affects assessment of the effects of vitamin C on the common cold.

Changes in leucocyte ascorbic acid during the common cold.

Leucocyte ascorbic acid was measured in 7 subjects during the common cold. There was a significant fall in L.A.A. to scorbutic levels within 24 hours of the onset of symptoms. By the fifth day the L.A.A. had returned to normal, which coincided with the cessation of symptoms. Absorption studies suggested 1g. ascorbic acid per day as a prophylactic dose and 6g. ascorbic acid per day as a therapeutic dose. The effect of such supplements of ascorbic acid in 4 episodes of the common cold in 3 subjects suggests that the L.A.A. pattern can be changed by this therapy. The implications are discussed.

Leucocyte ascorbic acid and pressure sores in paraplegia

Leucocyte ascorbic acid and pressure sores in paraplegia

Ascorbic Acid Depletion During Hemodialysis

Sixteen patients receiving long-term hemodialysis therapy demonstrated a decline in leukocyte ascorbic acid concentration of 26% during a single hemodialysis. Eight patients receiving 1 gm of ascorbic acid by mouth showed a 76% rise in leukocyte ascorbic acid concentration in three hours, while control subjects showed a 5% increase. When ascorbic acid was added to dialysate baths of 12 patients, plasma ascorbate levels were elevated by 26% at the end of dialysis, and leukocyte levels rose by 11%. Short-term hemodialysis therapy over five consecutive days produced a continuous decline in plasma and leukocyte ascorbate levels. Ascorbic acid loss from leukocytes and plasma during hemodialysis can be prevented by the addition of the vitamin to dialysate concentrate.

A study of the relationship between Hess tests and leucocyte ascorbic acid in a clinical trial.

1. The results of a previously reported controlled trial of vitamin supplementation of elderly hospital patients, in which capillary resistance was measured by the Hess test, were examined and analysed statistically.2. Capillary resistance was reduced during successive 3-monthly tests over a period of 12 months and the reduction was related to leucocyte ascorbic acid concentration.3. It is postulated that the rate of recovery from capillary trauma inflicted by the test was dependent upon the function of ascorbic acid in the hydroxylation of proline to hydroxyproline during collagen synthesis.

Leucocyte ascorbic acid levels after acute myocardial infarction.

Leucocyte ascorbic acid levels after acute myocardial infarction.

Effect of Tetracycline on Leucocyte Ascorbic Acid Levels

Fourteen men aged 73-94 showed a fall in leucocyte ascorbic acid levels during five days' treatment with 1 g of tetracycline daily. A control group of nine men aged 74-90 showed no fall in leucocyte ascorbic acid levels. Of the control group, three were treated with phenobarbitone 60 mg thrice daily, three with phenylbutazone 200 mg thrice daily, and three with aloxiprin 1,200 mg four times a day. A further two men aged 87 and 90 showed increased urinary excretion of ascorbic acid while receiving 1 g of tetracycline daily.

Ascorbic Acid Status of Alcoholics<xref ref-type="fn" rid="fn1"><sup>*</sup></xref>

The ascorbic acid status of 50 chronic alcoholics has been studied by measuring the leucocyte ascorbic acid levels (L.A.A.) and assessing the intake of vitamin C from diet histories. The mean (± S.D.) L.A.A. level of the group was 18.18±11.01μg/108W.B.C., which was significantly lower (P < 0.0005) than that of a matched group (27.41 ±7.59 μg/108W.B.C.). No clinical features of scurvy were noted in either group. The haematological status of the chronic alcoholics was also studied. The alcoholics were not anaemic but there was evidence from the serum iron and erythrocyte protoporphyrin results that in 13 out of 36 alcoholic patients the metabolism of iron was disturbed.

Leucocyte ascorbic acid levels and vitamin C intake in older people.

Leucocyte ascorbic acid (L.A.A.) levels and vitamin C intake were measured in a random sample of men and women aged 62-94 years. L.A.A. distributions are positively skewed but log normal. L.A.A. mean values show no age difference in men but are significantly lower in older women. The mean value for all women (23.88mug/10(8) cells) is significantly higher than that for all men (18.11 mug/10(8) cells). L.A.A. values are significantly higher in both sexes in the six months July to December. Vitamin C intake distributions are positively skewed but not improved by log transformation. No significant age or sex differences were found except that a significantly greater proportion of men over than of those under 70 years have intakes less than 30 mg daily. Mean intake is significantly higher in men but not in women in the six months April to September, though in both sexes a significantly greater proportion have intakes less than 30 mg daily in October to March compared with April to September. Fifty per cent. of men and 58% of women have intakes less than 30 mg daily, 23.6% of men and 28.1% of women have intakes less than 20 mg daily, and 4.7% of men and 3% of women have intakes less than 10 mg daily. These percentages increase during the winter. A moderate correlation is present between vitamin C intake and L.A.A. level. L.A.A. levels increase in parallel with but lag behind seasonal increases in vitamin C intake.

Ascorbic acid status in iron-deficiency anaemia.

Leucocyte ascorbic acid concentration declines with age. Patients with iron-deficiency anaemia have higher concentrations than normal while those with iron overload have a reduced concentration. It is suggested that these phenomena may be a result of reduced ascorbate catabolism in iron-deficiency anaemia and they provide support for the suggestion that the amount of iron in the tissues may be an important factor in determining ascorbic acid utilization.

Relationship Between Leucocyte and Plasma Ascorbic Acid Concentrations

Leucocyte and plasma ascorbic acid values were measured in healthy students, adult factory employees, and old people not receiving supplementary vitamin C and in healthy old people receiving 500 mg of vitamin C daily. Significant positive correlations between leucocyte and plasma ascorbic acid were found in all the groups. The regression lines differed significantly between one another within the sexes, but the pooled lines for each sex did not differ significantly in the unsupplemented groups. The relationship between plasma and leucocyte ascorbic acid values in the supplemented group differed significantly from that in the pooled unsupplemented groups.There was a limited range of variation in leucocyte ascorbic acid values compared with the range in plasma values in the supplemented group, whereas there was a wider range of variation in the leucocyte values in the unsupplemented groups. Leucocytes can therefore achieve a saturation level of ascorbic acid. Measurement of leucocyte ascorbic acid concentrations alone does not provide a reliable guide for the estimation of tissue status of ascorbic acid in normal individuals. Leucocyte concentrations provide a measure of the availability of ascorbic acid for storage, and plasma levels give an indication of its metabolic turnover rate. When these values are related the regression lines provide information about the storage and metabolism of ascorbic acid in normal individuals.

The Relationship between Serum Iron Levels and Ascorbic Acid Stores in Siderotic Bantu

Summary The concentrations of serum iron and of leucocyte ascorbic acid were measured in 35 adult Bantu subjects and were compared with the marrow gradings of storage iron. Ascorbic acid depletion was almost uniformly present in the 18 subjects with increased iron stores, but was uncommon in those with normal stores. On the other hand, there was no significant correlation between the serum iron levels and the marrow iron gradings.After therapy for 7 days with ascorbic acid the mean serum iron level rose significantly in the siderotic group but was unchanged in the group with normal stores. At this time there was a highly significant correlation between the levels of serum iron and the marrow iron gradings.It is concluded that the serum iron can be used as an index of iron overload in the Bantu only after repletion with ascorbic acid.

Urinary Hydroxyproline in the Elderly with Low Leucocyte Ascorbic Acid Levels

Fourteen elderly patients aged 58 to 91 with varying leucocyte ascorbic acid levels had urinary hydroxyproline/creatinine ratios measured before, during, and after treatment with ascorbic acid 1 g. daily for six days. The ratio increased during treatment in those patients whose initial ascorbic acid levels were below 15mug./10(8) white blood cells. It is suggested that collagen metabolism may be impaired in these patients, and that all such patients should receive ascorbic acid supplements.

Human Requirements of Ascorbic Acid

Longitudinal studies were carried out in 19 adult male volunteers in whom levels of ascorbic acid in leukocytes were followed at periodic intervals after fully saturating them with ascorbic acid. The subjects received diets providing 10-12 mg ascorbic acid daily. To those subjects in whom saturated levels were not maintained, a daily additional supplement of 10 mg of ascorbic acid was given. The results of the studies have indicated that maximal leukocyte concentration can be maintained by intakes of as little as 10 mg a day in some and by intakes of less than 22 mg a day in all subjects investigated.

The effect of ascorbic acid deficiency on desferrioxamine-induced urinary iron excretion.

Summary. The levels of tissue ascorbic acid tend to be low in subjects with iron overload. The present study was undertaken to find out whether this ascorbic acid deficiency affected the quantities of iron excreted in the urine after the administration of the iron chelate, desferrioxamine. Basal tests were done and were then repeated after 7 days of ascorbic acid therapy. Desferrioxamine‐induced urinary iron excretion increased by 88 per cent in 13 individuals with transfusional siderosis, 60 per cent in five with idiopathic haemochromatosis and 350 per cent in 12 Bantu subjects with dietary siderosis. Over the same period the mean leucocyte ascorbic acid concentrations rose by 164 per cent, 157 per cent and 551 per cent respectively. In contrast, no change was noted in either urinary iron excretion or in ascorbic acid concentrations in six normal white and six normal Bantu control subjects. These results suggest that tissue ascorbic acid concentrations should be restored to normal before desferrioxamine is used for either the diagnosis or the treatment of iron overload.

ASCORBIC-ACID LEVELS IN LEUCOCYTES OF PATIENTS WITH GASTROINTESTINAL HÆMORRHAGE

Leucocyte-ascorbic-acid (L.A.A.) levels were measured in sixty patients with gastrointestinal hæmorrhage, and the mean value of 14·2 μg. per 10 8 white blood-cells was significantly lower than that found in a matched peptic-ulcer control group (17·6) and in a healthy control group (23·7). The mean L.A.A. in uncomplicated peptic ulcer was significantly lower than that in the healthy control group. Levels were significantly lower in patients in whom aspirin or alcohol might have precipitated bleeding than in those in whom no precipitating factor was present: the degree of significance became much greater when patients over the age of 45 were considered separately. Twenty-three of the sixty patients with gastrointestinal haemorrhage were found to have a peptic ulcer, two had a hiatus hernia, and in thirty-five patients no specific cause was found. The association of low L.A.A. levels with aspirin or alcohol ingestion was present whatever the causation of hæmorrhage. Subclinical scurvy may be an additional factor in maintaining haemorrhage initially precipitated by aspirin or alcohol, and poor dietary intake of vitamin C seems the most probable explanation for the low L.A.A. levels observed.

Hypovitaminosis C and splenic rupture.

Two cases of splenic rupture in patients with hypovitaminosis C are reported. In Case 1 the deficiency was dietary in origin; this patient also had pernicious anaemia with an associated thrombocytopenia. These 2 abnormalities are considered significant in predisposing to splenic rupture on minimal trauma. In Case 2, in which the vitamin C deficiency was due to dietary deficiency and to malabsorption following partial gastrectomy, the low leucocyte ascorbic acid was the only abnormality detected, and the splenic rupture was spontaneous. A splenectomy was carried out and at operation there was noted to be persistent oozing of blood from muscle and subcutaneous tissue, and post-operatively, from the wound. It is suggested that in cases of spontaneous rupture of the spleen, as in any case of unexplained haemorrhage, the diagnosis of scurvy should be considered.

Osteoporosis in Johannesburg Bantu Males : Its Relationship to Siderosis and Ascorbic Acid Deficiency

An unusual variety of osteoporosis has previously been shown to occur in middleaged male Bantu subjects in Johannesburg, and associations with severe iron overload and with scurvy have been established. In the present investigation 110 asymptomatic manual laborers whose diets contained large amounts of iron and little ascorbic acid were studied. The mean leukocyte ascorbic acid concentration of this group was significantly lower than that of control groups. Seventeen (15%) of these subjects exhibited radiological evidence of vertebral osteoporosis, and the mean leukocyte ascorbic acid concentration of the osteoporotic individuals was significantly lower than that of the group as a whole. These results are consistent with the hypothesis that this unusual form of osteoporosis is the consequence of chronic ascorbic acid deficiency. A study of 71 Bantu male subjects dying of acute trauma and exhibiting no evidence of disease at necropsy was also carried out. A highly significant inverse correlation was established between the mineral density of the iliac crest bone and the hepatic iron concentration. This association may be due to the part played by severe iron overload in the pathogenesis of ascorbic acid deficiency in this population.

Leucocyte ascorbic acid levels in patients with malabsorption or previous gastric surgery.

Leucocyte ascorbic acid levels in patients with malabsorption or previous gastric surgery.