Sunshine in liquid form. That's essentially what Vitamin D supplements provide, to support healthy kidney function and perhaps prevent multiple sclerosis---both diseases associated with low levels of sunlight exposure. There is some evidence as well that adequate Vitamin D intake is important in the proper function of both the immune and cardiovascular systems.
Kidney Failure
Adequate Vitamin D is essential for healthy kidney function; a deficiency of the vitamin can lead to end-stage renal disease, or kidney failure. A study of 273 end-stage renal disease patients on kidney dialysis in Greece and Turkey revealed that 92 percent had Vitamin D deficiencies. The study was conducted by the Inonu Medical School in Malatya, Turkey. Results were published in the peer-reviewed journal Clinical Nephrology.
Disproportionate Impact on Minorities
Chronic kidney disease and its cardiovascular complications disproportionately impact minority populations.
Researchers at Drew University of Medicine and Science in Los Angeles say in a study published in the journal "Ethnic Disparities" that Vitamin D is crucial not only to kidney function, but also for healthy function of the immune and cardiovascular systems.
High rates of Vitamin D deficiency and quick progression to end-stage renal disease in minority populations are "highly relevant to national efforts to reduce health disparities," according to authors of this study.
Vitamin D3 Is Most Potent
Vitamin D acts in the body both through the endocrine system and by genetic expression. About 80 percent of Vitamin D metabolism is regulated by gene expression. In patients with end-stage renal disease, the regulation of Vitamin D by the endocrine system is disabled. But if the patient gets sufficient quantities of Vitamin D3, kidney function can be maintained without increasing the risk of high blood pressure, diabetes and cancer.
Research published in the "Clinical Journal of the Society of Nephrology" indicates that Vitamin D3 is "substantially more potent" than Vitamin D2 and sets a safe upper limit for D at 10,000 international units, or IU.
Sunlight
An Argentinian study looked at levels of Vitamin D in connection with sunlight exposure caused by seasonal variations. It also took into account body mass index, gender and low functional status among a group of 84 hemodialysis patients. Results were published in Hemodialysis International.
Researchers at the Fresenius Medical Center in Quilmes, Argentina, using Vitamin D standards from the (American) National Kidney Foundation, observed insufficiency of the vitamin in 54 percent of the patients and a deficiency in 23 percent.
Most importantly, they found that both insufficiency and deficiency of Vitamin D was highest at the end of winter, affecting 76 percent of the patients. Lower levels of the vitamin "seem to be from decreased sunlight exposure, female gender and increased body mass index," their report said.
Supplementation Recommended
Because the body depletes Vitamin D daily, scientists recommend oral doses of Vitamin D as the safest and most economical way to ensure adequate intake. It's recommended that you not exceed the upper limit for daily Vitamin D3 of 10,000 IU.
