Impact of Vitamin A Supplementation on Immune System in Multiple Sclerosis Patients
Impact of Vitamin A Supplementation on Immune System in Multiple Sclerosis Patients
The aim of this study is to study the comparison between the effects of supplementation with
 25000 IU preformed vitamin A (retinyl palmitate) or placebo for 6 months on immune system and
 Th1/Th2 balance in patients with Multiple Sclerosis.
Multiple Sclerosis (MS) is a chronic inflammatory disease where Th1 like responses from
 myelin-specific CD4+ T cells, as secretion of pro-inflammatory IFN-g, are believed to play a
 major role in the pathogenesis. The myelin-specific T cells that mediate tissue destruction
 in MS are believed to become activated outside the central nervous system (CNS) in lymphoid
 tissue and when they cross the blood brain barrier they will re-encounter their antigen.
 Immune deviation is the redirection of the immune response from most often Th1 like responses
 to Th2 like responses, even though the opposite can also occur. Vitamin A (VA) or VA-like
 analogs known as retinoids, are potent hormonal modifiers of type 1 or type 2 responses but a
 definitive description of their mechanism(s) of action is lacking. High level dietary vitamin
 A enhances Th2 cytokine production and IgA responses, and is likely to decrease Th1 cytokine
 production. Retinoic acid inhibits IL 12 production in activated macrophages, and RA
 pretreatment of macrophages reduces IFNγ production and increases IL4 production in antigen
 primed CD4 T cells. Supplemental treatment with vitamin A or retinoic acid (RA) decreases
 IFNγ and increases IL5, IL10, and IL4 production. Thus, vitamin A deficiency biases the
 immune response in a Th1 direction, whereas high level dietary vitamin A may bias the
 response in a Th2 direction.
Inclusion Criteria:

 Patients who have used interferon beta in last 3 months. Patients with 1-5 EDSS

 Exclusion Criteria:

 -  Patients who have diseases which affect on Th1/Th2 balance such as asthma, active
 viral infections, and autoimmune diseases, OR

 -  Patients who have allergy to vitamin A compounds, OR

 -  Patients who have used vitamin supplements in last 3 months.