Analysis of vitamin D deficiency in calcium stone-forming patients.
OBJECTIVE
The aim of this study is to analyse the percentage of hypovitaminosis D, as well as its relationship with the various parameters of calcium-phosphate metabolism.


METHODS
A case control study was conducted on 366 patients, divided into two groups: Group 1: 127 non-stone-forming patients, and Group 2: 239 calcium stone forming. A study was performed on calcium-phosphate metabolism and urinary lithogenic factors. The percentage of vitamin D deficiency (25-OH-vitamin D levels <20 ng/ml) between the groups was analysed and compared. The SPSS 20.0 statistics program was used for the analysis, with a p ≤ .05 being considered significant.


RESULTS
The mean age of Group 1 was 52.1 years compared to 49.6 years in Group 2, with no significant differences (p = .07). Vitamin D levels were lower in Group 2 compared to Group 1 (25.7 vs. 28.4 ng/ml, p = .02). A vitamin D deficiency was observed in 28 % of the Group 2 stone-forming patients versus 15.7 % in Group 1 (p = .009), with an odds ratio (OR) of 2.09 (95 % CI; 1.19-3.63). In the stone-forming patients with a vitamin D deficiency, the only difference observed was the higher levels of iPTH compared to those stone-formers with a normal vitamin D (56.9 vs. 45.5 pg/ml, respectively; p = .0001).


CONCLUSIONS
Calcium stone-forming patients have lower mean levels of vitamin D and a higher percentage of hypovitaminosis D than in non-stone-forming patients. This was only related to increased iPTH levels, with urine calcium and other lithogenic parameters having no obvious effect.
Primary Care, Health Centre of Pinos Puente, Programa de Doctorado de Medicina Clínica y Salud Pública, Granada University, Granada, Spain.
María Sierra
MS
Girón-Prieto
Institute IBS Granada, Plaza Ciudad de los Cármenes, No. 4, Granada, Spain.
María
M
Del Carmen Cano-García
Institute IBS Granada, Plaza Ciudad de los Cármenes, No. 4, Granada, Spain. arrabalp@ono.com.
Miguel Ángel
MÁ
Arrabal-Polo
Biochemical Department, Santa Ana Hospital, Granada, Spain.
Antonio
A
Poyatos-Andujar
Endocrinology Department, Granada University Hospital, Granada, Spain.
Miguel
M
Quesada-Charneco
Biochemical Department, Granada University Hospital, Granada, Spain.
Tomás
T
de Haro-Muñoz
Medicine Department, Granada University, Granada, Spain.
Salvador
S
Arias-Santiago
Surgery Department, Institute IBS Granada, Granada University, Granada, Spain.
Miguel
M
Arrabal-Martín
D000328:Adult; D002130:Calcium Phosphates / Q000652:urine*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D053040:Nephrolithiasis; D011379:Prognosis; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D014807:Vitamin D / Q000378:metabolism* / Q000652:urine; D014808:Vitamin D Deficiency / Q000150:complications* / Q000175:diagnosis
D002130:Calcium Phosphates; D014807:Vitamin D; C020243:calcium phosphate
Calcium; Calcium stones; Metabolism; Phosphorus; Vitamin D deficiency