Vitamin D: Its Role And Uses In Immunology
Deluca HF, Cantorna MT
FASEB J 2001 Dec;15(14):2579-85
University of Wisconsin-Madison, Department of Biochemistry, Madison, Wisconsin 53706, USA
PMID# 11726533; UI# 21583440
In recent years there has been an effort to understand possible NonCalcemic roles of Vitamin D, including its role in the Immune System and, in particular, on T-Cell-mediated Immunity.
Vitamin D receptors are found in significant concentrations in the T-Lymphocyte and Macrophage populations. However, their highest concentration is in the immature Immune Cells of the Thymus and the mature CD-8+ T-Lymphocytes.
The significant role of Vitamin D compounds as selective ImmunoSuppressants is illustrated by their ability to either prevent or markedly suppress animal models of AutoImmune Disease.
Results show that 1,25-DiHydroxyVitamin D3 can either prevent or markedly suppress Experimental AutoImmune Encephalomyelitis, Rheumatoid Arthritis, Systemic Lupus Erythematosus, Type I Diabetes, and Inflammatory Bowel Disease.
In almost every case, the action of the Vitamin D Hormone requires that the animals be maintained on a normal or high Calcium diet. Possible mechanisms of suppression of these AutoImmune Disorders by the Vitamin D Hormone have been presented.
The Vitamin D Hormone stimulates Transforming Growth Factor TGFß-1 and InterLeukin-4 (IL-4) production, which in turn may suppress inflammatory T-Cell activity.
In support of this, the Vitamin D Hormone is unable to suppress a murine model of the human disease Multiple Sclerosis in IL-4-deficient mice.
The results suggest an important role for Vitamin D in AutoImmune Disorders and provide a fertile and interesting area of research that may yield important new therapies.
Vitamin D: A Millenium Perspective
J Cell Biochem 2003;88(2):296-307
Boston University Medical Center, Department of Medicine, Section of Endocrinology, Diabetes, and Nutrition, Vitamin D Laboratory, Boston, Massachusetts 02118
PMID# 12520530; UI# 22407835
Vitamin D is one of the oldest Hormones that have been made in the earliest life forms for over 750 million years. Phytoplankton, Zooplankton, and most plants and animals that are exposed to sunlight have the capacity to make Vitamin D.
Vitamin D is critically important for the development, growth, and maintenance of a healthy skeleton from birth until death.
The major function of Vitamin D is to maintain Calcium homeostasis. It accomplishes this by increasing the efficiency of the Intestine to absorb dietary Calcium.
When there is inadequate Calcium in the diet to satisfy the body's Calcium requirement, Vitamin D communicates to the Osteoblasts that signal Osteoclast Precursors to mature and dissolve the Calcium stored in the bone.
Vitamin D is metabolized in the Liver and then in the Kidney to 1,25-DiHydroxyVitamin D [1,25(OH)(2)D]. 1,25(OH)(2)D receptors (VDR) are present not only in the Intestine and bone, but in a wide variety of other tissues.
Including the Brain, Heart, Stomach, Pancreas, activated T and B-Lymphocytes, Skin, Gonads, etc. 1,25(OH)(2)D is one of the most potent substances to inhibit proliferation of both normal and hyperproliferative cells and induce them to mature.
It is also recognized that a wide variety of tissues, including Colon, Prostate, Breast, and Skin have the enzymatic machinery to produce 1,25(OH)(2)D. 1,25(OH)(2)D and its analogs have been developed for treating the HyperProliferative disease Psoriasis.
Vitamin D deficiency is a major unrecognized health problem. Not only does it cause Rickets in children, Osteomalacia and Osteoporosis in adults, but may have long lasting effects.
Chronic Vitamin D deficiency may have serious adverse consequences, including increased risk of Hypertension, Multiple Sclerosis, Cancers of the Colon, Prostate, Breast, and Ovary, and type 1 Diabetes.
There needs to be a better appreciation of the importance of Vitamin D for overall health and well being.
Copyright 2002 Wiley-Liss, Inc.
Multiple Sclerosis And Vitamin D: An Update
VanAmerongen BM, Dijkstra CD, Lips P, Polman CH
Eur J Clin Nutr 2004 Aug;58(8):1095-109
VU Medical Center, Department of Molecular Cell Biology and Immunology, Amsterdam, The Netherlands
MS is a chronic, Immune-mediated Inflammatory and NeuroDegenerative Disease of the Central Nervous System (CNS), with an Etiology that is not yet fully understood. The prevalence of MS is highest where environmental supplies of Vitamin D are lowest.
It is well recognized that the active Hormonal form of Vitamin D, 1,25-DiHydroxyVitamin D (1,25-(OH)(2)D), is a natural ImmunoRegulator with anti-inflammatory action.
The mechanism by which Vitamin D nutrition is thought to influence MS involves Paracrine or Autocrine metabolism of 25OHD by cells expressing the enzyme 1 -OHase in peripheral tissues involved in Immune and Neural function.
Administration of the active metabolite 1,25-(OH)(2)D in mice and rats with Experimental Allergic Encephalomyelitis (EAE, an animal model of MS) not only prevented, but also reduced disease activity.
1,25-(OH)(2)D alters Dendritic Cell and T-Cell function and regulates Macrophages in EAE. Interestingly, 1,25-(OH)(2)D is thought to be operating on CNS constituent cells as well.
Vitamin D deficiency is caused by insufficient sunlight exposure or low dietary Vitamin (D3) intake. Subtle defects in Vitamin D metabolism, including genetic polymorphisms related to Vitamin D, might possibly be involved as well.
Optimal 25OHD Serum concentrations, throughout the year, may be beneficial for patients with MS, both to obtain Immune-mediated suppression of disease activity, and also to decrease disease-related complications, including increased bone resorption, fractures, and muscle weakness.