Regelmatig inname hoge dosis vitamine D nodig voor goede bloedwaarden*
Uit een Amerikaanse studie blijkt regelmatig hoge dosis vitamine D nodig zijn om goede bloedwaarden vitamine D te handhaven. Goede bloedwaarden vitamine D zijn belangrijk voor een goed immuunsysteem, goede botopbouw, tegen hart- en vaatziektes, diabetes, infecties zoals virusinfecties waaronder griep en diverse autoimmuunziektes. Deelnemers kregen 8 weken lang iedere week een dosis van 1.250 mcg vitamine en daarna om de twee weken een zelfde dosis van 1.250 mcg. Deelnemers met aan het begin van de studie lage bloedwaarden, gemiddeld < 19 ng/ml hadden na 8 weken bloedwaarden van 37 ng/ml en na de tweeweekse periode bloedwaarden van gemiddeld 47 ng/ml. Bij de andere deelnemers, die gemiddeld een beginwaarde van 27 ng/ml hadden, was na de eerste 8 weken de gemiddelde bloedwaarden vitamine D 47 ng/ml.
Nadien kregen de deelnemers zes jaar lang de tweewekelijkse dosis van 1.250 mcg. Op het eind van de studie bleek iedereen goede bloedwaarden vitamine D behouden te hebben zonder enige vorm van nadelige effecten.
Vitamin D Deficiency Prevented By Weekly And Biweekly Vitamin D2
Boston University School of Medicine researchers (BUSM) have found that 50,000 International Units (IU) of vitamin D2, given weekly for eight weeks, effectively treats vitamin D deficiency. Vitamin D2 is a mainstay for the prevention and treatment of vitamin D deficiency in children and adults. Continued treatment with the same dose of vitamin D2 every other week for up to six years after the initial eight-week period prevents vitamin D deficiency from recurring with no toxicity. The BUSM study appears online in the journal Archives of Internal Medicine.
Vitamin D is essential for strong bones because it helps the body absorb calcium and phosphorus from the food we eat. Vitamin D deficiency can lead to rickets in children and the painful bone disease osteomalacia in adults. Vitamin D deficiency can also cause osteoporosis and has been linked to increased risk of cancer, heart disease, diabetes, autoimmune diseases and infectious diseases including influenza, according to senior author Michael F. Holick, PhD, MD, director of the Bone Healthcare Clinic and the Vitamin D, Skin and Bone Research Laboratory at Boston University School of
Medicine.
Of the 86 patients researchers studied, 41 patients who were vitamin D deficient received eight weeks of 50,000 IU of vitamin D2 weekly prior to starting maintenance therapy. For those patients, the mean pre-treatment 25-hydroxyvitamin D status (25(OH)D) level was 19 ng/ml, which increased to 37 ng/ml after eight weeks of weekly therapy. These patients were then treated with 50,000 IU of vitamin D2 every other week and had a mean final 25(OH)D level of 47 ng/ml.
For the 45 patients who received only maintenance therapy of 50,000 IU of vitamin D2 every two weeks, the mean pre-treatment 25(OH)D level was 27 ng/ml and the mean final level was 47 ng/ml.
"Vitamin D2 is effective in raising 25(OH)D levels when given in physiologic and pharmacologic doses and is a simple method to treat and prevent vitamin D deficiency," said Holick, who is also director of the General Clinical Research Unit and professor of medicine, physiology and biophysics at BUSM. "While treating and preventing vitamin D deficiency, these large doses of vitamin D2 do not lead to vitamin D toxicity."
According to Holick, this is the first study demonstrating the efficacy of a prescription therapy to prevent vitamin D deficiency longterm in routine clinical practice.
Quest Diagnostics, the nation's leading provider of diagnostics testing, information and services, analyzed the specimens used in the study.
Source:
Gina DiGravio
Boston University Medical Center (November 2009)
