Vitamin D kann für Knochen ohne Nutzen sein

(DGE) – Auf der Jahrestagung der American Society of Bone and Mineral Research (ASBMR) berichtete am 24. September 2019 Meryl LeBoff  (1) über eine Subanalyse der VITAL-Studie (vgl. 2) an gesunden von Männern und Frauen.

Elisabeth Hlavinka (3) referierte diesen Beitrag  in MEDPAGE TODAY unter dem griffigen Titel: Vit D Supplements Flop Again for Bone Health. A couple of years of vitamin D supplementation had no effect on bone mineral density (BMD) or bone loss in healthy people, according to an ancillary study of the VITAL trial presented here. In a subcohort involving 771 adults who received no bone active medications, 2.000 IU daily vitamin D supplements showed no effect on absolute or percent change in BMD compared with placebo, with the differences between groups measured at the spine, hip, or whole body, all <0.5% (so Meryl LeBoff vom Brigham and Women’s Hospital in Boston). “Among 687 patients with 2-year follow-up data, supplementation was not associated with changes in volumetric BMD versus placebo. Daily supplements of vitamin D for 2 years did not improve bone density or structure in generally healthy men and women in the U.S. not selected for vitamin D insufficiency“.  LeBoff fuhr fort:  „Participants may have already reached the vitamin D level needed for bone health”.  In weiteren Substudien wurde beim ASBMR-Kongress berichtet, dass Vitamin D Supplementierung auch keinen Einfluss auf Stürze hatte: „Specifically, in participants with at least one fall at baseline, vitamin D supplementation versus placebo did not affect subsequent falls, injurious falls, or those resulting in doctor or hospital visits”.

Felicia Cosman von der Columbia University New York, welche die Sitzung moderierte, kommentierte die Subanalyse der Vital-Studie (4): „I think the take-home message is that many healthy ambulatory people 55 years of age and older do not need supplement vitamin D, certainly not 2000 IU daily, so people should not routinely take this. Indeed, one recently published study (5) has even suggested that high dose vitamin D may be detrimental to bone health. However, that message is very different to those with osteoporosis”.

In MEDPAGE TODAY schreibt Hlavinka über diese Studie weiter: “The VITAL findings are in line with results from another trial, the Calgary Vitamin D Study (5) reported last month, which showed no bone benefit, in fact it found a possible adverse effect with the high doses of vitamin D in healthy people.  About 300 patients have been randomized to receive either low (400 IU), moderate (4,000 IU), or high (10,000) levels of vitamin D.  The trial involved  men and women, ages 55-70, with basal vitamin D levels from 30 to 125 nmol/L (12 to 50 ng/mL). The group had a mean age of 62 and 54% were male. Their serum 25-hydroxyvitamin D (25-OH-D) levels were well above the targeted recommendation”.  Nach 3-jähriger Behandlung mit 4000 oder 10 000 IU/ Vitamin D pro Tag fand man im Vergleich zu 400 IU/Tag einen statistisch signifikant geringeren Knochenmineralgehalt am Radius, an der Tibia mit  täglich 10 000 IU.

In Orlando wurde nun ein Update dieser Studie präsentiert, welcher ergab, dass, entgegen den Erwartungen der Autoren, die Vitamin D – Supplemente zu keiner Zunahme von Koronarverkalkungen geführt haben: „Our study corroborates other trials, such as the VITAL trial, that have not shown any effect of vitamin D supplementation on cardiovascular events or mortality,“ so E.Billington, die Erstautorin des Calgary-Study-Update  in Orlando,  (6).

Kommentar
Diese Resultate liegen ganz auf der Linie des Referenten, welcher dem, wie man in der Presse oft lesen konnte „Vitamin D -Hype“ stets abwartend-distanziert gegenübergestanden hat, dies in vielen Blogbeiträgen geäußert hat und sich jetzt zunehmend bestätigt sieht.

Helmut Schatz