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Effects of vitamin E and C supplementation on oxidative stress and viral load in HIV-infected subjects

Allard, Johane P.1,2; Aghdassi, Elaheh1; Chau, Jenny1; Tam, Carolyn1; Kovacs, Colin M.1; Salit, Irving E.1; Walmsley, Sharon L.1

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HIV infection results in the progressive impairment of immune response leading to the development of AIDS. Amongst the mechanisms contributing to this progression, oxidative stress induced by the production of reactive oxygen species (ROS) during activation of polymorphonuclear leukocytes and macrophages [1] may play a critical role. In vitro experiments [2] have demonstrated that ROS can specifically activate the transcription factor nuclear factor (NF)-κB to induce the expression and replication of HIV [2,3]. Addition of antioxidant vitamins to the system blocked this activation and inhibited HIV replication [4–6].

Several studies have now documented an excessive production of ROS in the HIV-infected population, regardless of the extent of their immunosuppression, based on measurements of lipid peroxidation indices in plasma and expired breath [7–13]. This increase in lipid peroxidation may be moderated by a normal antioxidant defense system that scavenges the ROS. The latter depends on the integrity of an enzymatic system that requires adequate intake of trace minerals such as selenium, copper, zinc, and manganese, and on the presence of adequate levels of vitamin E, C, A and carotenoids in the cytoplasm and lipid membrane of the cells. Previous studies have shown that patients with HIV infection may have deficiencies in many of these components, including selenium [11,14], vitamin A [15], E [16], C [17] and carotenoids [11].

Of these antioxidants, α-tocopherol (vitamin E) is the most potent and most abundant lipophilic antioxidant in vivo [18] as well as an immunoenhancer [19]. Vitamin C is the major water-soluble antioxidant and acts as the first defense against ROS in whole blood [20] and plasma [21]. In addition, a cooperative interaction exists between the two vitamins, vitamin C being important in regenerating vitamin E during the antioxidant defense process [22].

Large sums of money are spent by the HIV-infected population on various vitamin and mineral supplements each year but no clinical trials have rigorously investigated the effect of supplementation of these antioxidant vitamins in the HIV-infected population. In this study, we hypothesized that supplementation of vitamin E (DL-α-tocopherol acetate) and vitamin C will result in a decrease in oxidative stress, which could have clinical implications on the course of HIV.

Subjects and methods

This study is a randomized double-blind placebo-controlled trial. Stable HIV-positive subjects from amongst those of participating physicians were approached for the study between April 1995 and August 1996. Patients could be on any combination of antiviral therapy providing that any therapy was started 4 weeks prior to study entry and remained stable for the duration of the study. This trial was conducted before the widespread use of combination therapies and protease inhibitors. Subjects were eligible if they had no active opportunistic infection. Exclusion criteria were as follows: smoking, initiation of antioxidant vitamin therapy prior to the study, hyperlipidemia, diabetes, kidney/liver dysfunction, intractable diarrhea (at least six liquid stools daily), vomiting or evidence of gastrointestinal bleeding. Patients underwent an initial screening, which included history (medical, smoking, diet, alcohol and supplemental vitamin intake), anthropometric data (weight, height), and review of biochemical results (complete blood count, glucose, creatinine, urea, liver enzymes). Of 62 potentially eligible patients who were screened, nine patients did not want to participate and four were not recommended by their physicians because of poor drug compliance. Forty-nine subjects were enrolled and 40 completed the study. Amongst the nine who did not complete the study, three were randomized to the vitamin group (two had epigastric discomfort, one was unable to keep the 3-month follow-up appointment) and six were randomized to the placebo group (all were unable to keep their 3-month follow-up appointment). All nine patients had baseline and follow-up measurements (month 1 or 2 of the study) performed for all the parameters and were thus included in the statistical analysis on an intention-to-treat basis.

Patients enrolled were placed on a controlled diet that provided a polyunsaturated to saturated fatty acid ratio of 0.3 : 1 for 2 weeks prior to randomization and continued during the study period. They also received dietary counselling to maximize and standardize their intake of food rich in vitamins. Patients were randomly assigned (using a random number table) to receive daily either 800 IU DL-α-tocopherol acetate (vitamin E, two capsules) and ascorbic acid (vitamin C) 1000 mg daily (two tablets), or matched placebo (two capsules or two tablets), distributed by an independent nurse. The placebo for vitamin E contained soybean oil and the placebo for vitamin C contained dextrose. Both supplements and placebo were coded, had the same taste, appeared identical and were prepared specifically for this study (Hoffman-LaRoche, Nutley, New Jersey, USA). The code was not broken until all patients completed the therapy and all the analysis were performed. Therefore, subjects, observers and laboratory personnel were unaware of the nature of the supplement given. Compliance with the supplement or placebo intake was verified by counting leftover medication and by measuring plasma vitamin concentrations. Subjects were advised to continue their normal activity and to report any unusual symptoms. Patients were required to record their food intake for 3 days (2 week days and 1 weekend day) at the beginning and the end of the study, including all food and beverages consumed, their portion size and method of preparation. Patients were assessed at baseline and at 3 months. At each study visit, anthropometry, review of food records and laboratory tests were also performed.

Diagnosis of HIV-associated opportunistic and other infections were reported in the chart by physicians during the 6 months after randomization. Data were collected by chart review at the end of the study. A 6-month period was chosen because of a possible carryover effect from the vitamins. The sample size chosen was inadequate to demonstrate differences in the number of infections between groups. The recording was performed for the purpose of future clinical trials.

For vitamin levels, lipid peroxides, malondialdehyde (MDA) and viral load, blood was collected in EDTA, and for zinc and selenium, in trace-element-free tubes. The samples were put in ice and centrifuged promptly at 2400 r.p.m. at 4°C for 10 min. The plasma was removed and frozen at −70°C until analysis. Plasma for vitamin C assays was stabilized immediately with 100 g/l metaphosphoric acid (HPO3; 2.0 ml plasma plus 2.0 ml HPO3). The food records were analyzed using a nutrient database (The Minnesota Nutrition Data System, Version 2.7, Minneapolis, Minnesota, USA).

Written informed consent was obtained from all participants. The study protocol was approved by the Toronto Hospital Committee for Research on Human Subjects.

Laboratory analyses

Breath alkane output

Breath analysis was performed as described previously [23]. Briefly, subjects were first required to breathe hydrocarbon-free air for 4 min to wash contaminating hydrocarbons from their lungs. Subsequently, expired air was collected for 2 min and analyzed by gas chromatography (Shimadzu 6-AM GC, Shimadzu Seisgkusho, Kyoto, Japan). Pentane was analyzed on a Porasil D column (Chromatographic Specialties, Inc., Brockville, Ontario, Canada) using a calibration curve derived from known concentrations of the gases. The concentration of breath pentane was expressed in pmol/kg/min.

Lipid peroxide determination

Plasma lipid peroxides were determined using the Kamiya Biochemicals LPO kit (Thousand Oaks, California, USA). In this procedure, hemoglobin catalyses the reaction of hydroperoxides with a methylene blue derivative forming an equimolar concentration of methylene blue. Lipid peroxides are quantified by calorimetry at 675 nm and methylene blue formation is measured. For plasma high performance liquid chromatography (HPLC)-separated MDA determination, the method described by Draper [24] was used.

Vitamin and trace element determination

Retinol and other carotenoids including β-carotene were analyzed by HPLC according to the method of Sapuntzakis et al. [25]. In this method, a reverse-phase C18 column was used with an isocratic solvent system (methanol–acetonitrile–tetrahydrofuran, 50 : 45 : 5 vol/vol/vol) following a hexane extraction using 200 μl serum sample. α- and γ-tocopherol were analyzed using an isocratic reverse-phase HPLC and fluorescence spectrophotometry at 294 nm according to the method of Nata et al. [26].

Samples were analyzed for vitamin C by spectrophotometry method [27]. In this method, total biologically active vitamin C concentrations were determined spectrophotometrically at 521 nm using 2,4-dinitrophenyl–hydrazine as chromogen.

Plasma zinc was analyzed using atomic absorption spectrophotometer (Varian Techtron Model 1200, Varian Associates Canada Ltd, Malton, Ontario, Canada) by the method described by Wolman et al. [28]. Plasma selenium was measured using atomic absorption spectrophotometry at 196 nm [29]. In this method, nickel salt was added as a matrix modifier to prevent volatilization of selenium during ashing.

Plasma HIV viral load was assessed using a standardized PCR kit for RNA with all reagents provided by Roche Molecular Systems (Mississauga, Ontario, Canada) [30].

Data were expressed as means (SEM). Statistical significance was defined as P < 0.05. The primary objective was to compare the change in measurements between 0 and 3 months, between the placebo and vitamin-supplemented groups, using unpaired t-test for continuous variables. Linear regression was performed to analyze the association between viral load at baseline versus the change after 3 months. Analysis were performed on an intention-to-treat basis. It was estimated that 20 patients in each group would be required to detect a difference of 20% in breath alkane output, with 90% power using a 5% significance level (two-sided). SAS software was used for the analysis [31].


The baseline characteristics of the patients are outlined in Table 1. There were no significant differences between the groups at baseline with respect to demography, CD4 cell counts, dietary intake and number of patients on various reverse transcriptase inhibitors. In the supplement group, four patients were on no anti-retrovirals, two were on monotherapy, and 20 were on a combination therapy. In the placebo group, four were on no antiretrovirals, one was on monotherapy, and 17 were on combination therapy. None of the patients received protease inhibitors during the study period. Twenty-three patients (22 men, one woman) were randomized to the placebo group and 26 (25 men, one woman) to the supplemented group. Compliance was excellent on the basis of the number of pills returned and was similar between groups (vitamin E, 93.5 ± 2.2%; vitamin C, 93.6 ± 2.2%; placebo E, 95.8 ± 2.2%; placebo C, 96.0 ± 2.2%).

Table 1
Table 1:
Baseline characteristics of patients and dietary intake.

During the study, there was no significant change in body mass index or dietary intake in either group. There was a significant increase in plasma vitamin E and C concentrations in the supplemented group compared with the placebo group (Table 2) as expected. Plasma retinol, carotenoids, zinc and selenium remained unchanged during the study, suggesting that other supplementation was not occurring.

Table 2
Table 2:
Plasma micronutrient data.

Lipid peroxidation measured by breath pentane output, plasma MDA and lipid peroxides was not significantly different between the two groups at baseline, although there was a trend for the placebo group to have a higher breath pentane output and a lower MDA value (Table 3). There was a significant decrease in these measurements in the vitamin-supplemented group at 3 months when compared with the placebo group.

Table 3
Table 3:
Oxidative stress and viral load data.

Plasma HIV viral load (Table 3) was similar at baseline between the two groups. The change after 3 months of supplementation was observed to be more favorable in the vitamin-supplemented group with a mean decrease of 0.45 ± 0.39 log10 copies/ml compared with a mean increase of 0.50 ± 0.40 log10 copies/ml for the placebo group (P = 0.1; 95% confidence interval, −0.21 to −2.14). Linear regression analysis used to evaluate the association between viral load at baseline and the change after 3 months was significant (P = 0.026) indicating that the change after 3 months depended on the initial score.

There was no relationship between baseline plasma vitamin E or C concentrations and viral load and the response did not differ between those who had lower concentrations of antioxidant vitamins compared with those who had higher concentrations. There was no statistically significant difference between the groups with regard to new AIDS-defining opportunistic infections, HIV-associated or other infections (Table 4).

Table 4
Table 4:
New and recurrent infections.


This study is the first randomized controlled trial to demonstrate that, in an HIV-positive population, daily supplementation of 800 IU vitamin E and 1000 mg vitamin C significantly decreases oxidative stress and produces a trend towards a reduction in HIV viral load.

HIV-infected populations have been shown to be oxidatively stressed and to have significantly lower plasma antioxidant micronutrient concentrations such as vitamin C, vitamin E, β-carotene and selenium than seronegative controls [11]. In the present study, the plasma concentrations of these antioxidant vitamins were also low at baseline. Others have also reported reduced plasma selenium [32,33], vitamin E [16] and vitamin C concentrations [17]. It was therefore appropriate to test the effect of vitamin E and C supplementation in this population. Both asymptomatic and AIDS patients were included because in a previous study we did not detect a difference in lipid peroxidation or micronutrient deficiencies between these two subsets [11]. During the study period, antiviral drugs were kept stable and thus did not confound with the observed results.

At baseline, both groups were similar, although there was a trend towards a higher breath pentane and lower plasma MDA values in the placebo group. For breath pentane, we interpreted this as a bias against our results. In our previous studies [34,35], we found that the response to antioxidant supplementation was usually higher in those who had higher values of pentane at baseline. Therefore, in the vitamin-supplemented group, the effect expected should have been smaller, although it remained significant.

The reason for the lower plasma MDA values at baseline in the placebo group is unclear. Values in both groups were lower than those reported previously [8,12,13], probably because the method we used was more specific [24]. Other antioxidant micronutrients were measured in the plasma and found to be stable during the study. This excluded the effect of sudden dietary changes or use of other antioxidant supplements on our results.

The dose of vitamins used in the study was based mostly on our previous experience with smokers, a population also known to be oxidatively stressed. In these subjects, vitamin E 800 IU per day was found to significantly decrease lipid peroxidation [35]. In contrast, 500 mg vitamin C per day produced a significant effect only in smokers of more than 15 pack-years (unpublished). Observational studies with vitamin C over 750 mg and vitamin E 130 IU per day have also suggested a beneficial effect on risk of AIDS or disease progression [36,37]. Therefore, the dose of vitamins used in this study seemed appropriate. We also decided to use the combination of vitamin E and C because vitamin C regenerates vitamin E during the antioxidant defense process [22].

During this study, no concurrent multivitamin supplements were used in order to try to minimize confounding effect in the treatment or control arm, as previously reported [38]. Patients were monitored with food records and their intake of micronutrients met or exceeded the recommended daily allowances (vitamin E, 9–10 mg; vitamin C, 40–60 mg). In addition, at the beginning of the study, subjects received dietary counselling to maximize and standardize their intake of vitamins from food sources.

The methods of measuring lipid peroxidation are well recognized. For MDA determination, we used an HPLC procedure [24] that resolves the problem of specificity associated with the spectrophotometric method but markedly enhanced the sensitivity. Breath pentane output was used by our group in previous studies [34,35] and evolves from the peroxidation of ω-6 fatty acids. The volatile hydrocarbon gases are produced by the β-scission of polyunsaturated fatty acids and are passed from the lungs into the expired air [23]. In human studies, the measurement of these alkanes in the breath is non-invasive and has been used and validated as a measure of lipid peroxidation [23,39,40]. Because the intake of polyunsaturated fatty acids can influence lipid peroxidation [41], the subjects were given instructions about their dietary fat intake 2 weeks prior to the measurements. Smoking [42], liver disease [43] and alcohol consumption [44] can also affect these measurements. The subjects were screened prior to be enrolled and excluded if these confounders were present.

Increased oxidative stress found in HIV populations [7–10] may have some clinical significance. In vitro evidence implicates oxidative stress in the stimulation of HIV replication through activation of NF-κB to induce the expression and replication of HIV-1 in a human T-cell line. Addition of antioxidant vitamins blocked activation of NF-κB and inhibited HIV replication [4–6]. Similar effects may occur in vivo, as demonstrated by the trend towards a reduction in HIV viral load that was observed with vitamin supplementation. Potential synergistic activity between combination of antiviral therapy and antioxidant vitamin supplementation should be explored.

This study was unable to demonstrate any difference in the number of AIDS-defining, HIV-associated or nonassociated infections. However, we feel that this could be further investigated, especially since vitamin E is known to be an immunoenhancer and can improve immune function in other immunosuppressed populations [19].

There have been no other clinical trials using a combination of vitamin E and C or other antioxidant micronutrients in HIV populations. Trials with β-carotene studying the effect on immune functions were initially promising [45,46] but a more recent study was negative [38]. This negative result may have been attributed to the use of multivitamins in both arms. A non-randomized trial [47] performed in HIV-infected patients showed no significant effect from selenium and β-carotene supplementation on superoxide dismutase activity, an antioxidant enzyme, compared with baseline; but another enzyme playing a central role in ROS metabolism, glutathione peroxidase activity, increased. No clinical outcomes were measured.

The results of this study may have some implications for maternal and child health [48–50], especially in developing countries [51], since increased oxidative stress has been associated with adverse pregnancy and birth outcomes [48,49]. Furthermore, the effect of antioxidant supplementation on mother-to-infant transmission could be investigated since, in the present study, viral load reduction was similar to that seen with zidovudine, a drug known to reduce HIV transmission from mother to infant [50]. Finally, HIV-infected smokers may benefit even more from antioxidant supplementation since smoking alone has been associated with an increase in ROS production and a decrease in antioxidant plasma concentrations [34,35].

In conclusion, this study showed that vitamin E and C supplementation significantly decreases oxidative stress in HIV-infected individuals. Furthermore, with this vitamin supplementation there was a trend towards a reduction in viral load suggesting that there may be some clinical benefit worthy of larger clinical trials. Since combination antiretroviral therapies containing protease inhibitors are limited for economic reasons to only about 10% of HIV-infected individuals in the world, consideration of the potential for this antioxidant therapy remains important for the developing world [52]. It could have great benefit, perhaps similar to the effect of vitamin A supplementation on childhood mortality in developing countries [52,53].


1. Das UN, Podma M, Sogar PS, Ramesh G, Koratkar R: Stimulation of free radical generation in human leukocytes by various agents including tumor necrosis factor is a calmodulin-dependent process. Biochem Biophys Res Commun 1990, 67:1030–1036.
2. Schreck R, Rieber P, Baeuerle PA: Reactive oxygen intermediates as apparently widely used messengers in the activation of the NF- κ B transcription factor and HIV-1. EMBO J 1991, 10:2247–2258.
3. Wong GHW, McHugh T, Weber R, Goeddel DV: Tumor necrosis factor alpha selectively sensitizes human immunodeficiency virus infected cells to heat and radiation. Proc Natl Acad Sci USA 1991, 88:4372–4376.
4. Harakeh S, Jariwalla RJ, Pauling L: Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells. Proc Natl Acad Sci USA 1990, 87:7245–7249.
5. Harakeh S, Jariwalla RJ: Comparative study of the anti-HIV activities of ascorbate and thiol-containing reducing agents in chronically HIV-infected cells. Am J Clin Nutr 1991, 54 (suppl 6):1231S–1235S.
6. Gagu SR, Beckman BS, Rangan SRS, Agrawal KC: Increased therapeutic efficacy of zidovudine in combination with vitamin E. Biochem Biophys Res Commun 1989, 165:401–407.
7. Halliwell B, Cross CE: Reactive oxygen species, antioxidants, and acquired immunodeficiency syndrome. Arch Intern Med 1991, 151:29–31.
8. Revillard JP, Vincent CMA: Lipid peroxidation in human immunodeficiency virus infection. J Acquir Immune Defic Syndr 1992, 5:637–638.
9. Postaire E, Massias L, Lopez O, Mollereau M, Hazebroucq G: Alkane measurements in human deficiency virus infection. In Oxidative Stress, Cell Activation and Viral Infection. Edited by Pasquier Birkhauser P. Basel: Verlag; 1994:333–340.
10. Sonnerborg A, Carlin G, Akerlund B, Jarstrand C: Increased production of malondialdehyde in patients with HIV infection. Scand J Infect Dis 1988, 20:287–290.
11. Allard JP, Aghdassi E, Chau J, Salit I, Walmsley S: Oxidative stress and plasma antioxidant micronutrients in humans with HIV infection. Am J Clin Nutr 1998, 67:143–147.
12. Malvy DJM, Richard MJ, Arnaud J, Favier A, Amedee-Manesme O: Relationship of plasma malondialdehyde, vitamin E and antioxidant micronutrients to human immunodeficiency virus-1 seropositivity. Clin Chim Acta 1994, 224:89–94.
13. Coutellier A, Bonnefont-Rousselot D, Delattre J, et al.: Stress oxidatif chez 29 sujets seropositifs. Presse Med 1992, 21:1809–1812.
14. Cirelli A, Ciardi M, de Simone C, et al.: Serum selenium concentration and disease progress in patients with HIV-infection. Clin Biochem 1991, 24:211–214.
15. Semba RD, Graham NMH, Caiaffa WT: Increased mortality associated with vitamin A deficiency during human immunodeficiency virus type 1 infection. Arch Intern Med 1993, 153:2149–2154.
16. Javier JJ, Fodyce-Baum MK, Beach RS: Antioxidant micronutrients and immune function in HIV-1 infection [abstract]. FASEB Proc 1990, 4(Suppl. 4):A940.
17. Bogden JD, Baker H, Frank O, et al.: Micronutrient status and human immunodeficiency virus (HIV) infection. Ann N Y Acad Sci 1990, 587:189–195.
18. Burton GW, Joyce A, Ingold KU: Is vitamin E the only lipid-soluble, chain-breaking antioxidant in human blood plasma and erythrocyte membranes? Arch Biochem Biophys 1983, 221:281–290.
19. Meydani SN, Beharka AA: Recent developments in vitamin E and the immune response. Nutr Rev 1996, 56 (suppl II):S49–S58.
20. Niki E, Yamamoto Y, Takahashi M, et al.: Free-radical mediated damage of blood and its inhibition by antioxidants. J Nutr Sci Vitaminol (Tokyo) 1988, 34:507–512.
21. Frei B, England L, Ames BN: Ascorbate is an outstanding antioxidant in human blood plasma. Proc Natl Acad Sci USA 1989, 86:6377–6381.
22. Niki E, Noguchi N, Tsuchihashi H, Gotoh N: Interaction among vitamin C, vitamin E, and beta-carotene. Am J Clin Nutr 1995, 62(Suppl. 6):1322S–1326S.
23. Lemoyne M, Van Gossum A, Kurian R, Ostro M, Jeejeebhoy KN: Breath pentane analysis as an index of lipid peroxidation: a functional test of vitamin E status. Am J Clin Nutr 1987, 46:267–272.
24. Draper HH, Squires EJ, Mahmoodi H, Wu J, Agarwal S, Hadley M: A comparative evaluation of thiobarbituric acid methods for the determination of malondialdehyde in biological materials. Free Radical Biol Med 1993, 15:353–363.
25. Sapuntzakis MS, Bowen PE, Kikendall JW, Burgess M: Simultaneous determination of serum retinol and various carotenoids: their distribution in middle-aged men and women. J Micronutr Anal 1987, 3:27–45.
26. Nata C, Sapuntzakis MS, Bhagavan H, Bowen P: Low serum levels of carotenoids in sickle cell anemia. Eur J Haematol 1988, 41:131–135.
27. Bessey OA, Lowry OH, Brock MJ: Quantitative determination of dehydro ascorbic acid in small amounts of white cells and platelets. J Biol Chem 1947, 168:197–205.
28. Wolman SL, Anderson GH, Marliss EB, Jeejeebohy KN: Zinc in total parenteral nutrition: requirements and metabolic effects. Gastroenterology 1979, 76:458–467.
29. Pleban PA, Munyani A, Beachum J: Determination of selenium concentration and glutathione peroxidase activity in plasma and erythrocytes. Clin Chem 1982, 28:311–316.
30. Mullis KB, Faloona FA: Specific synthesis of DNAin vitrovia a polymerase-catalyzed chain reaction. Methods Enzymol 1987, 155:335–350.
31. SAS Institute: SAS/STAT User's Guide Release 6.03 Edition. Cary: SAS Institute, Inc.; 1988:549.
32. Beach RS, Mantero-Atienza E, Shor-Posner G, et al.: Specific nutrient abnormalities in asymptomatic HIV-1 infection. AIDS. 1992, 6:701–708.
33. Dworkin BM, Rosenthal WS, Wormser GP, Weiss L: Selenium deficiency in the acquired immunodeficiency syndrome. J Parenter Enteral Nutr 1986, 10:405–407.
34. Allard JP, Royall D, Kurian R, Muggli R, Jeejeebhoy KN: Effect of beta-carotene supplementation on lipid peroxidation in humans. Am J Clin Nutr 1994, 59:884–890.
35. Hoshino E, Shariff R, Van Gossum A, et al.: Vitamin E suppresses increased lipid peroxidation in cigarette smokers. J Parenter Enteral Nutr 1990, 14:300–305.
36. Tang AM, Graham NMH, Kirby AJ, McCall DL, Willett WC, Saah AJ: Dietary micronutrient intake and risk of progression to AIDS in HIV-1-infected homosexual men. Am J Epidemiol 1993, 138:937–951.
37. Abrams B, Duncan D, Hertz-Picciotto I: A prospective study of dietary intake and acquired immune deficiency syndrome in HIV-seropositive homosexual men. J Acquir Immune Defic Syndr 1993, 6:949–958.
38. Coodley GO, Coodley MK, Lusk R, et al.: Beta-carotene in HIV infection: an extended evaluation. AIDS 1996, 10:967–973.
39. Dumelin EE, Tappell AL: Hydrocarbon gases produced duringin vitroperoxidation of polyunsaturated fatty acids and decomposition of preformed hydroperoxides. Lipids 1977, 12:894–900.
40. Filser JG, Bolt HM, Muliawan H, Kappus H: Quantitative evaluation of ethane andn-pentane as indicators of lipid peroxidationin vivo. Arch Toxicol 1983, 52:135–147.
41. Kivits G, Ganguli-Swarttouw MA, Christ EJ: The composition of alkanes in exhaled air of rats as a result of lipid peroxidationin vivo. Biochim Biophys Acta 1981, 665:559–570.
42. Wade CR, van Rij AM: In vivolipid peroxidation in man as measured by the exhalation of volatile hydrocarbons: the effect of cigarette smoke inhalation. Proc Univ Otago Med Sch 1986, 64:75–76.
43. Hartmut F, Hintze T, Bimboes S, Remmer H: Monitoring lipid peroxidation by breath analysis: endogenous hydrocarbons and their metabolic elimination. Toxicol Appl Pharmacol 1980, 56:337–344.
44. Litov RE, Gee DL, Downey JE, Tappel AL: The role of peroxidation during chronic and acute exposure to ethanol as determined by pentane expiration in the rat. Lipids 1981, 16:52–63.
45. Garewal SH, Ampel NM, Watson RR, Prabhala RH, Dols CL: A preliminary trial of beta-carotene in subjects infected with the human immunodeficiency virus. J Nutr 1992, 122:728–732.
46. Coodley GO, Nelson HD, Loveless MO, Folk C: Beta-carotene in HIV infection. J Acquir Immune Defic Syndr 1993, 6:272–276.
47. Delmas-Beauvieux MC, Peuchant E, Couchouron A, et al.: The enzymatic antioxidant system in blood and glutathione status in human immunodeficiency virus (HIV)-infected patients: effects of supplementation with selenium or beta-carotene. Am J Clin Nutr 1996, 64:101–107.
48. Mikhail MS, Anyaegbunam A, Garfinkel D, Palan PR, Basu J, Romney SL: Preeclampsia and antioxidant nutrients: decreased plasma levels of reduced ascorbic acid, alpha-tocopherol, and beta-carotene in women with preeclampsia. Am J Obstet Gynecol 1994, 171:150–157.
49. Ziari SA, Mireles VL, Cantu CG, et al.: Serum vitamin A, vitamin E, and beta-carotene levels in preeclamptic women in northern Nigeria. Am J Perinatol 1996, 13:287–291.
50. Sperling RS, Shapiro DE, Coombs RW, et al.: Maternal viral load, zidovudine treatment, and the risk of transmission of human immunodeficiency virus type 1 from mother to infant. N Engl J Med 1996, 335:1621–1629.
51. UNAIDS, WHO: Report on the Global HIV/AIDS Epidemic. Geneva: UNAIDS/WHO; 1997.
52. Kotler DP: Antioxidant therapy and HIV infection: 1998 [editorial]. Am J Clin Nutr 1998, 67:7–9.
53. Rahmathullah L, Underwood BA, Thulasiraj RD, et al.: Reduced mortality among children in Southern India receiving a small weekly dose of vitamin A. N Engl J Med 1990, 323:929–935.

Lipid peroxidation; antioxidants; vitamins; α-tocopherol; ascorbic acid; HIV; AIDS; viral load

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