Vitamins delay onset of Aids
Of special importance are vitamin A, vitamin C, vitamin E, certain B-group vitamins and minerals such as selenium, zinc and iron. Since the vitamin content of food can be damaged during cooking, it is better to cook vegetables for a short time only. Vegetables will lose some of their vitamins and minerals if soaked for a long time.
The skins and kernels of grains and legumes contain vitamins, in particular of the B-group. Processed refined grains may have lost many of their vitamins, minerals and proteins; so whole grains such as brown bread and unrefined cereals are better sources than white bread and refined cereals.
Fortified cereals and bread are preferred because of their higher vitamin content. If a person has diarrhoea, however, whole unrefined grains and cereals should be avoided since these insoluble fibres make the diarrhoea worse. Soluble fibre foods such as bananas are recommended. Soluble fibres will bind water in the gut and, therefore, reduce diarrhoea.
Vitamin A helps regulate the immune system. Vitamin A may help white blood cells fight opportunistic infections. Vitamin A deficiency increases the severity of diseases such as diarrhoea. Vitamin A supplementation to pre-school children is known to decrease the risks of mortality and morbidity from some forms of diarrhoea, measles, HIV infection, and malaria. Benefits for severe diarrhoea could be attributable to the fact that vitamin A sustains the architectural lining of the gut, whereas positive effects among HIV-infected children could also be related to increased production of immune cells. But some studies have reported no conclusive evidence for a direct effect of vitamin A supplementation on immune system activation.
Good vitamin A sources are dark green, yellow, orange and red vegetables and fruit. These include spinach, pumpkin, cassava leaves, green peppers, squash, carrots, amaranth, yellow peaches, apricots, papaya and mangoes. Vitamin A is also contained in red palm oil, yellow maize, orange and yellow sweet potatoes, egg yolk and liver.
Vitamin C helps to protect the body from infection and aids in recovery. It is found particularly in citrus fruits such as oranges, grapefruit, lemons and mandarins. Guavas, mangoes, tomatoes and potatoes are also good sources of vitamin C. Vitamin E protects cells and aids resistance to infection. Foods containing vitamin E are green leafy vegetables, vegetable oils, peanuts and egg yolk.
The vitamin B-group is necessary to keep the immune and nervous system healthy. Good food sources include white beans, potatoes, meat, fish, chicken, watermelon, maize, grains, nuts, avocados, broccoli and green leafy vegetables.
Multivitamin supplementation with vitamin B complex, vitamin C, and vitamin E significantly delayed the onset of AIDS among HIV-infected women. Supplementation with vitamin A alone did not give good results. Thus currently available data provides no consistent evidence for beneficial effects of vitamin A. Additional studies with these age groups are needed.
In the United States, higher intakes of vitamins ‘ including vitamins B1, B2, and B6; niacin; vitamin C; and vitamin E ‘ were associated with slower disease progression. Similarly, supplementation with B-complex vitamins was beneficial among black South Africans infected with HIV. Men with lower serum vitamin E levels or vitamin B12 levels were more likely than those with higher levels to have progression to AIDS.
In a study in Thailand, multivitamin supplementation was associated with a significant reduction in mortality among patients with baseline CD4+ cell counts below 100 cells per cubic millimetre but had no significant effects on CD4+ cell counts, viral load, or clinical disease progression.
In Tanzania, supplementation with multivitamins reduced the incidence of complications including oral thrush, oral ulcers, and difficulty in swallowing. Nausea, vomiting, and diarrhoea were also less frequent among women who received multivitamins. Vitamins and micronutrients protect the integrity of oral and gastrointestinal surfaces and enhance local and systemic immunity.
Many researchers have observed significantly higher CD4+, CD8+, and CD3+ cell counts and lower viral loads among women who received multivitamins than among those who did not receive multivitamins. Other studies have shown that vitamins B, C and E enhance cellular immunity which prevents the proliferation of HIV. B vitamins increased the numbers of CD4+ cells among HIV-infected men in the US.
Vitamins enhance the production of cytokines, chemical substances that act like loudspeakers of the immune system; they activate cells that destroy HIV-infected cells.
The beneficial effects of multivitamins on the immune system can be sustained for an average period of five years.
In addition to enhancing immunity, multivitamins may also reduce HIV production, as indicated by the significant reduction in viral load. HIV production in the body is increased by oxidative stress. Components of multivitamin supplements, particularly vitamins C and E, are potent antioxidants that block oxidative stress and HIV production thereby reducing the viral load.
In one study, HIV-positive patients, those who received daily supplements of both vitamin E (800 IU) and vitamin C (1000 mg) for three months had a significant reduction in oxidative stress and a trend toward a reduced viral load. It seems that vitamin B and vitamins C and E reduce the risk of wasting. But the benefits, with respect to immunological and virological outcomes, in some of these studies, are small relative to the effects of triple antiretroviral therapy. Multivitamin and micronutrient supplementation should not be a substitute for ARVs.
l KC is a lecturer at the University of Namibia. Email: email@example.com