Vitamin A

A deficiency of vitamin A is associated with increased morbidity and mortality, most likely because of increased severity of infections [85].Vita-min A and related retinoids maintain the integrity of epithelial boundaries and the production of mucosal secretions. Some of the immunological abnormalities following vitamin A inadequacies include a reduced number of leukocytes, reduced lymphoid organ weights, reduced circulating levels of complement, impaired T-cell functions, and decreased resistance to immunogenic tumours.

Vitamin A supplementation studies showed decreases in respiratory infections and neutrophil counts and increases in reticuloendothelial system function, lymphocyte proliferation, tumour resistance, graft rejection and cytotoxic T-cell activities. Supplementation above that required to maintain normal vitamin A stores results in adjuvant effects. Excess vitamin A increases antibody and cell-mediated immune responses, stimulates Kupffer cells and potentiates some types of liver toxicity and gouty arthritis [86]. The inhibition of T-cell apoptosis by retinoic acid may contribute to its adjuvant effect [87].

The vitamin A precursor p-carotene is generally considered an antioxidant with activities that are independent of its provitamin A function. Some of its reported benefits include protecting host cells and tissues from oxidation by the respiratory burst and promoting lymphocyte proliferation, T-cell functions, cytokine production and cell-mediated cytotoxicity. However, Bates [88] cautioned that carotenoids can exhibit both pro-oxidant and antioxidant activity.

Osteoarthritis

Osteoarthritis

Thank you for deciding to learn more about the disorder, Osteoarthritis. Inside these pages, you will learn what it is, who is most at risk for developing it, what causes it, and some treatment plans to help those that do have it feel better. While there is no definitive “cure” for Osteoarthritis, there are ways in which individuals can improve their quality of life and change the discomfort level to one that can be tolerated on a daily basis.

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