Vitamin C supplementation in the elderly: a 17-month trial in an old persons' home

Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration

BACKGROUND

There is inconclusive evidence from observational studies to suggest that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C, and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD).

OBJECTIVES

To determine whether or not taking antioxidant vitamin or mineral supplements, or both, prevent the development of AMD.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 2), MEDLINE Ovid (1946 to 29 March 2017), Embase Ovid (1947 to 29 March 2017), AMED (Allied and Complementary Medicine Database) (1985 to 29 March 2017), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/); searched 29 March 2017, the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 29 March 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 29 March 2017 and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 29 March 2017. We did not use any date or language restrictions in the electronic searches for trials.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing an antioxidant vitamin or mineral supplement (alone or in combination) to control.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5; the other author checked the data entry. We pooled data using a fixed-effect model. We graded the certainty of the evidence using GRADE.

MAIN RESULTS

We included a total of five RCTs in this review with data available for 76,756 people. The trials were conducted in Australia, Finland, and the USA, and investigated vitamin C, vitamin E, beta-carotene, and multivitamin supplements. All trials were judged to be at low risk of bias.Four studies reported the comparison of vitamin E with placebo. Average treatment and follow-up duration ranged from 4 to 10 years. Data were available for a total of 55,614 participants. There was evidence that vitamin E supplements do not prevent the development of any AMD (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.90 to 1.06; high-certainty evidence), and may slightly increase the risk of late AMD (RR 1.22, 95% CI 0.89 to 1.67; moderate-certainty evidence) compared with placebo. Only one study (941 participants) reported data separately for neovascular AMD and geographic atrophy. There were 10 cases of neovascular AMD (RR 3.62, 95% CI 0.77 to 16.95; very low-certainty evidence), and four cases of geographic atrophy (RR 2.71, 95% CI 0.28 to 26.0; very low-certainty evidence). Two trials reported similar numbers of adverse events in the vitamin E and placebo groups. Another trial reported excess of haemorrhagic strokes in the vitamin E group (39 versus 23 events, hazard ratio 1.74, 95% CI 1.04 to 2.91, low-certainty evidence).Two studies reported the comparison of beta-carotene with placebo. These studies took place in Finland and the USA. Both trials enrolled men only. Average treatment and follow-up duration was 6 years and 12 years. Data were available for a total of 22,083 participants. There was evidence that beta-carotene supplements did not prevent any AMD (RR 1.00, 95% CI 0.88 to 1.14; high-certainty evidence) nor have an important effect on late AMD (RR 0.90, 95% CI 0.65 to 1.24; moderate-certainty evidence). Only one study (941 participants) reported data separately for neovascular AMD and geographic atrophy. There were 10 cases of neovascular AMD (RR 0.61, 95% CI 0.17 to 2.15; very low-certainty evidence) and 4 cases of geographic atrophy (RR 0.31 95% CI 0.03 to 2.93; very low-certainty evidence). Beta-carotene was associated with increased risk of lung cancer in people who smoked.One study reported the comparison of vitamin C with placebo, and multivitamin (Centrum Silver) versus placebo. This was a study in men in the USA with average treatment duration and follow-up of 8 years for vitamin C and 11 years for multivitamin. Data were available for a total of 14,236 participants. AMD was assessed by self-report followed by medical record review. There was evidence that vitamin C supplementation did not prevent any AMD (RR 0.96, 95% CI 0.79 to 1.18; high-certainty evidence) or late AMD (RR 0.94, 0.61 to 1.46; moderate-certainty evidence). There was a slight increased risk of any AMD (RR 1.21, 95% CI 1.02 to 1.43; moderate-certainty evidence) and late AMD (RR 1.22, 95% CI 0.88 to 1.69; moderate-certainty evidence) in the multivitamin group. Neovascular AMD and geographic atrophy were not reported separately. Adverse effects were not reported but there was possible increased risk of skin rashes in the multivitamin group.Adverse effects were not consistently reported in these eye studies, but there is evidence from other large studies that beta-carotene increases the risk of lung cancer in people who smoke or who have been exposed to asbestos.None of the studies reported quality of life or resource use and costs.

AUTHORS' CONCLUSIONS

Taking vitamin E or beta-carotene supplements will not prevent or delay the onset of AMD. The same probably applies to vitamin C and the multivitamin (Centrum Silver) investigated in the one trial reported to date. There is no evidence with respect to other antioxidant supplements, such as lutein and zeaxanthin. Although generally regarded as safe, vitamin supplements may have harmful effects, and clear evidence of benefit is needed before they can be recommended. People with AMD should see the related Cochrane Review on antioxidant vitamin and mineral supplements for slowing the progression of AMD, written by the same review team.

Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration

BACKGROUND

There is inconclusive evidence from observational studies to suggest that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD).

OBJECTIVES

To examine the evidence as to whether or not taking antioxidant vitamin or mineral supplements prevents the development of AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 12), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 26 January 2012.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5 and the other author checked the data entry. We pooled data using a fixed-effect model.

MAIN RESULTS

We included four RCTs in this review; 62,520 people were included in the analyses. The trials were conducted in Australia, Finland and the USA and investigated vitamin E and beta-carotene supplements. Overall the quality of the evidence was high. People who took these supplements were not at decreased (or increased) risk of developing AMD. The pooled risk ratio for any antioxidant supplement in the prevention of any AMD was 0.98 (95% confidence interval 0.89 to 1.08) and for advanced AMD was 1.05 (95% CI 0.80 to 1.39). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol alone.

AUTHORS' CONCLUSIONS

There is accumulating evidence that taking vitamin E or beta-carotene supplements will not prevent or delay the onset of AMD. There is no evidence with respect to other antioxidant supplements, such as vitamin C, lutein and zeaxanthin, or any of the commonly marketed multivitamin combinations. Although generally regarded as safe, vitamin supplements may have harmful effects and clear evidence of benefit is needed before they can be recommended. People with AMD should see the related Cochrane review 'Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration' written by the same review team.

Scurvy in hospitalized elderly patients

OBJECTIVES

The aim of this study was to systematically screen hospitalized elderly patients for clinical symptoms of scurvy and to confirm the diagnosis with biological measures.

SETTINGS

Geriatric acute care ward.

MEASUREMENTS

Scurvy symptoms (one or more among perifollicular hyperkeratosis, petechiae or bruises, haemorrhagic features caused by venous puncture, severe gingivitis). We compared associated diseases, nutritional status, need for assistance for feeding, serum albumin, transthyretin, B9 and B12 vitamins, iron status and Serum Ascorbic Acid Level (SAAL) and outcome (in-hospital mortality) between scurvy and scurvy free patients.

RESULTS

18 patients with clinical symptoms of scurvy (scurvy group) were identified out of 145 consecutive patients (12%). They were compared to 23 consecutive control patients with no clinical symptoms of scurvy (scurvy-free group). SAAL was significantly lower (1.09 +/- 1.06 vs 4.87 +/- 4.2 mg x L-1, p < .001) and vitamin C deficiency more frequent (94 vs 30 %, p < .001) in the scurvy group. Moreover, in scurvy group, coronary heart disease (39 vs 9 %, p=.028), need for assistance for feeding (56 vs 13 %, p=.006) and in-hospital deaths (44 vs 9 %, p=.012) were more frequent.

CONCLUSION

Ninety-four percent of patients with clinical symptoms of scurvy had vitamin C deficiency. Our results suggest that in hospitalized elderly patients, clinical symptoms allow scurvy diagnosis. Scurvy could be a frequent disease in elderly patients admitted to acute geriatric ward.

Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration

BACKGROUND

Some observational studies have suggested that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD).

OBJECTIVES

The aim of this review was to examine the evidence as to whether or not taking vitamin or mineral supplements prevents the development of AMD.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library (2007, Issue 3), MEDLINE (1966 to August 2007), SIGLE (1980 to 2005/03), EMBASE (1980 to August 2007), National Research Register (2007, Issue 3), AMED (1985 to January 2006) and PubMed (on 24 January 2006 covering last 60 days), reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies.

SELECTION CRITERIA

We included all randomised trials comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control. We included only studies where supplementation had been given for at least one year.

DATA COLLECTION AND ANALYSIS

Both review authors independently extracted data and assessed trial quality. Data were pooled using a fixed-effect model.

MAIN RESULTS

Three randomised controlled trials were included in this review (23,099 people randomised). These trials investigated alpha-tocopherol and beta-carotene supplements. There was no evidence that antioxidant vitamin supplementation prevented or delayed the onset of AMD. The pooled risk ratio for any age-related maculopathy (ARM) was 1.04 (95% CI 0.92 to 1.18), for AMD (late ARM) was 1.03 (95% CI 0.74 to 1.43). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol.

AUTHORS' CONCLUSIONS

There is no evidence to date that the general population should take antioxidant vitamin and mineral supplements to prevent or delay the onset of AMD. There are several large ongoing trials. People with AMD should see the related Cochrane review "Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration" written by the same author.

Antioxidant vitamin and mineral supplementation for preventing age-related macular degeneration

BACKGROUND

Some observational studies have suggested that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration.

OBJECTIVES

The aim of this review is to examine the evidence as to whether or not taking vitamin or mineral supplements prevents the development of age-related macular degeneration.

SEARCH STRATEGY

We searched the Cochrane Eyes and Vision Group specialised register, the Cochrane Controlled Trials Register - Central, MEDLINE, reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies. The most recent searches were conducted in June 1999.

SELECTION CRITERIA

All randomised trials comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control were included. We included only studies where supplementation had been given for at least one year.

DATA COLLECTION AND ANALYSIS

Both reviewers independently extracted data and assessed trial quality. Currently there is only one published trial included in the review so no data synthesis was conducted.

MAIN RESULTS

One trial is included in the review. This was a primary prevention trial in Finnish male smokers with four treatment groups: alpha-tocopherol alone, beta-carotene alone, alpha-tocopherol and beta-carotene, placebo. The add-on maculopathy study was conducted in a subset of the main trial cohort. 269 cases of maculopathy (14 late stage age-related macular degeneration) were identified. There was no association of age-related macular degeneration with treatment.

REVIEWER'S CONCLUSIONS

There is no evidence to date that people without age-related macular degeneration should take antioxidant vitamin and mineral supplements to prevent or delay the onset of the disease. The results of five large ongoing trials are awaited.

Immunologic modulation by vitamin C in the elderly

Aging is associated with a decline in both humoral-mediated and cellular-mediated immunity. These aberrations may contribute to morbidity and mortality in the elderly. Since we have previously shown that vitamin C enhances in vitro and in vivo immune functions in young healthy volunteers, we studied the effects of vitamin C on certain immunologic parameters in an elderly population. In vitro lymphocyte proliferation to the mitogen concanavalin-A was significantly less when compared to a young control group. When lymphocytes from the elderly were pre-incubated overnight and cultured in the presence of 10 micrograms/ml of vitamin C, mitogen-stimulated lymphocyte proliferation was similar to that from controls without vitamin C in culture. Having demonstrated significant in vitro immunoenhancement with vitamin C, we next studied the effects of oral ingestion of 2 g of vitamin C daily on certain in vitro and in vivo immunologic parameters in the elderly. When compared with a placebo-treated group, 3 weeks of vitamin C treatment did not effect in vitro mitogen-stimulated lymphocyte proliferation or in vivo reactivity to common skin test antigens. The augmenting effects of in vitro vitamin C suggest that this essential vitamin may be an effective agent in modulating aberrant immunologic functions in the elderly. The clinical significance of these findings requires further study.

Nutritional status of residents in Part III accommodation

THE NUTRITIONAL status of residents of old people's homes, compared to individuals living at home, has been assessed. The residents had significantly lower means intakes of ascorbic acid, thiamin, pyridoxin, folic acid, nicotinic acid and protein. These findings were reflected in markedly lower circulating levels of ascorbic acid and folic acid in the residents. The data suggests that there should be reappraisal of the nourishment provided for the elderly in Part III accommodation.

Increased ascorbic acid content in chronic lymphocytic leukemia B lymphocytes

Human lymphocyte extracts analyzed by high-performance liquid chromatography reveal a major UV-absorbing peak that was shown to be ascorbic acid by spectral, chemical, and enzymatic criteria. Because this peak appeared very prominent in the elution profile of chronic lymphocytic leukemia (CLL) lymphocyte extracts, we measured the ascorbic acid content in lymphocytes from the blood of normal subjects and untreated patients with chronic lymphocytic leukemia. A significantly higher concentration of 111 +/- 15.3 nmol per 10(8) cells (mean +/- SEM) was found in CLL lymphocytes than in normal blood lymphocytes, which contained 42.2 +/- 3.3 nmol per 10(8) cells. Selective enrichment with B and T cells showed that this difference was limited to the chronic lymphocytic leukemia B cell, which had a 5- to 15-fold higher content of ascorbic acid than normal B cells had. In contrast, the ascorbic acid level was similar in normal and CLL T cells. The very high ascorbic acid content provides the chronic lymphocytic leukemia B cell with a reducing substance that could react with oxidants or free radicals.

Long-term vitamin status and dietary intake of healthy elderly subjects. 2. Vitamin C

1. Long-term clinical and biochemical vitamin C (ascorbic acid and dehydroascorbic acid) status and dietary intake of vitamin C were monitored for 18 months in twenty-three relatively-healthy elderly subjects living at home in the north of England.

2. Plasma vitamin C showed a strong positive correlation with buffy-coat vitamin C both cross-sectionally between subjects and longitudinally within subjects; plasma levels, therefore, were almost as good an index of long-term status as buffy-coat levels.

3. Vitamin C intake was strongly correlated with plasma and with buffy-coat levels both between subjects and within subjects. This contrasts with the poor correlation observed between riboflavin intake and biochemical riboflavin status in the same subjects.

4. Subjects with relatively high average intakes showed considerable seasonal variation, and several widely-spaced measurements would be needed to characterize their long-term status accurately. Those with low average intakes and blood levels showed little variation during the study.

5. The strongest within-subject correlation was obtained by relating the biochemical values to the 7 d dietary intake directly preceding the biochemical analysis. Blood and tissue levels therefore appear to be strongly related to the current dietary intake.

6. Although some subjects had blood vitamin C levels consistently within the region associated with biochemical deficiency, none showed clinical evidence of specific deficiency symptoms.

7. After the main study, fifteen of the subjects received supplementary vitamin C for 2 months. Plasma and buffy-coat levels rose sharphy, but fell to presupplementation levels within 1 month of withdrawal, emphasizing the transitory nature of increased tissue levels. No significant changes were detected in the following collagen-related urinary ratios: hydroxyproline: creatinine, proline: creatinine, proline: total amino-nitrogen and proline: hydroxyproline in hydrolysates either of whole urine or of various fractions. These variables thus appear to be insensitive to short-term changes in vitamin C status over the ranges encountered in this study.

Vitamin needs of the elderly

Vitamin deficiency is a result of gradual depletion of body stores secondary to poor dietary habits or to disease. Marginal or preclinical vitamin deficiency results in nonspecific symptoms such as malaise, irritability or somnolence, loss of appetite and weight, and impairment of psychologic and physical performance socially or at work. These signs precede clinical signs of disease. The elderly are particularly vulnerable to vitamin deficiency because of the high incidence of illness and disability in the later years of life and because of other common problems, such as low income, poor appetite, and social isolation.

Ascorbic acid supplementation in the treatment of pressure-sores

In a prospective double-blind controlled trial the effect of large doses of ascorbic acid on the healing of pressure-sores has been assessed. 20 surgical patients were studied, the pressure areas being assessed by serial photography and ulcer tracings. The mean ascorbic-acid levels in treated and non-treated groups one month after the start of treatment were 65.6 and 25.8 mug per 10-8 white blood-cells. In the group treated with ascorbic acid there was a mean reduction in pressure-sore area of 84% after one month compared with 42.7% in the placebo group. These findings are statistically significant (P less than 0.005) and suggest that ascorbic acid may accelerate the healing of pressure-sores.

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.

Atherosclerosis and vitamin C

Following the chance observation that the author's serum-cholesterol could be varied between 140 and 230 mg. per 100 ml. by increasing the vitamin-C intake or by lowering it, a study was undertaken in healthy individuals and in patients with atherosclerosis. In healthy people under the age of 25, cholesterol levels tended to fall when 1 g. of vitamin C per day was added to an otherwise normal diet. In older people, no consistent pattern of serum-cholesterol change was seen, but in patients with a history of atherosclerosis, most of whom were on clofibrate and/or anticoagulants, the serum-cholesterol increased in the weeks when vitamin-C supplements increased in the weeks when vitamin-C supplements were given. It is suggested that this rise in serum-cholesterol is caused by mobilisation of the arterial cholesterol.

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.

A survey of 216 elderly men and women in general practice

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