Send to:

Choose Destination
See comment in PubMed Commons below
Swiss Med Wkly. 2012 Sep 4;142:w13672. doi: 10.4414/smw.2012.13672.

Preserved circannual rhythm of vitamin D in kidney transplant patients.

Author information

  • 1Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Switzerland.



A high prevalence of vitamin D insufficiency has been found in the general population, in patients with chronic kidney disease and in kidney transplant patients. During winter there is a higher prevalence of vitamin D insufficiency due to the lack of solar ultraviolet B (UVB) exposure. Kidney transplant patients are advised to avoid sun exposure because of their high risk of skin cancer. This is considered to be one of the main reasons for the very high prevalence of vitamin D insufficiency in these patients. Whether circannual rhythm of vitamin D is totally reversed in kidney transplant patients is not known.


In this single centre prospective observational study, 50 kidney transplant patients visiting our outpatient clinic in January and February 2011 were included. Serum concentration of 25-hydroxvitamin D (25[OH]D), 1-25-hydroxvitamin D (1-25[OH]D) and intact parathormone (iPTH) were measured at study entry and 6 months later in summer.


A total of 90% (45/50) of the study population had vitamin D deficiency 25(OH)D (<50 nmol/l) during winter. There was a rise of 25(OH)D in 94% (47/50) of patients from winter to summer (p <0.0001) leading to a decline of 25(OH)D deficiency from 90 to 60%, to a rise of 25(OH)D insufficiency from 6 to 26% and normal 25(OH)D from 4 to 14%, respectively (p = 0.0024).


Vitamin D insufficiency during winter is very common in kidney transplant patients at our centre. Despite avoidance of exposure to UVB there is a preserved circannual rhythm of vitamin D in kidney transplant patients.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Icon for EMH Swiss Medical Publishers Ltd.
    Loading ...
    Write to the Help Desk