Related post: Both hypervitaminosis D3 and hypovitaminosis D3 cause premature aging of CNS

What is the problem?

Vitamin D deficiency has been linked not only to bone health, but also some types of cancer, lowered immune function, and kidney disease. Recent studies showed that vitamin D may preserve cognitive function exerting its neuroprotective effects via the vitamin D receptors abundantly expressed in regions frequently affected in cases of neurodegenerative diseases such as the hypothalamus, substantia nigra, cortex and hippocampus. An increased incidence of Alzheimer’s disease, schizophrenia and depression (including depression as a symptom of fibromyalgia and chronic fatigue syndrome, Clinical Rheumatology 1434-9949, 26, 4, April 2007) was proved to be associated with vitamin D deficiency  (J Chem Neuroanat 2005;29:21-30.)

What are the causes?

• Decreased bioavailability of vitamin D can be caused by malabsorption often present in cystic fibrosis, celiac disease, Whipple’s disease, Crohn’s disease, bypass surgery, and medications that reduce cholesterol absorption.
• Obesity also educes availability of vitamin D locking it in the body fat depots.
• Anticonvulsants, glucocorticoids
• Inadequate sun exposure including that due to excessive sunscreen use

(N Engl J Med 2007;357:266-81)

Prevention by supplementation

Most experts agree that current recommendations for daily intake of vitamin D are in fact inadequate: without adequate sun exposure, children and adults require approximately 800 to 1000 IU per day (J Clin Invest 2006; 116:2062-72; Primer on the metabolic bone diseases and disorders of mineral metabolism. 6th ed. Washington, DC: American  Society for Bone and Mineral Research, 2006:129-37; Endocrinology. Philadelphia: W.B.Saunders, 2001:1009-28)