Kimball et al. Cholecalciferol Plus Calcium Suppresses Abnormal PBMC Reactivity in Patients with Multiple Sclerosis. J Clin Endocrinol Metab. 2011 Jun 22. [Epub ahead of print]
The active metabolite of vitamin D is a potent modulator of immune cells. In this study the investigators' determined whether vitamin D, a sun-dependent nutrient can affect the cells athat are associated with the immune abnormalities in MS. Treated MS'ers received increasing doses of vitamin D (4,000-40,000 IU/d) plus calcium (1200 mg/d), followed by equilibration to a moderate, physiological dose of vitamin D of 10,000 IU/d (the amount you get from 20-30 minutes of sun exposure in mid summer). Control subjects did not receive supplements. Results
: At 12 months, the average serum vitamin D concentrations were 83 nmol/liter and 179 nmol/liter in control and treated participants, respectively (P < 0.001). In treated MS'ers, the abnormal immunological responses of lymphocytes (an important immune cell in MS) against components of nerve cells and myelin were suppressed. Interpretation
: MS-associated, abnormal T cell responses that are believed to trigger MS were suppressed in subjects with vitamin D concentrations in their blood higher than 100 nmol/liter.
"This study would indicate that you would need to keep your serum vitamin D levels above 100 nmol/litre to have effects on the immune system; this would mean most of us taking 10,000U of vitamin D per day; in comparison we only need 400U per day to prevent bone thinning. This is why we are trying to get public health officials to recognise this and increase the RDA of vitamin D."
"Interestingly, if you lived as a hunter-gatherer, i.e. out in the open as our ancestors did, your serum levels would be above 100nmol/litre. We know this from studies done on farmers, life guards and other groups of people who work outdoors. It makes you think about what we are doing to ourselves by changing, and continuing to change, our lifestyles so dramatically over the last 2 generations. Any thoughts about what the digital revolution is doing to our immune systems?"