Factors associated with serum 25-hydroxyvitamin D concentrations in older people in Europe: the EUREYE study

Background/Objectives We aimed to describe serum 25-hydroxyvitamin D (25OHD) concentrations in older Europeans and to investigate associations between 25OHD and lifestyle factors, including dietary intake and supplement use. Subjects/Methods Men and women aged ≥ 65 years were recruited from seven centres across north to south Europe. Serum 25OHD 2 and 25OHD 3 concentrations were measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) in 4495 samples and total 25OHD (25OHD 2 + 25OHD 3 ) was adjusted for season of blood collection. Results The mean (25th, 75th quartile) of seasonally adjusted 25OHD was 46 (34, 65) nmol/L, with the highest concentration of 25OHD in Bergen [61 (49, 79) nmol/L], and the lowest in Paris [36 (24, 57) nmol/L)]. Vitamin D deficiency (25–50 nmol/L) and vitamin D insufficiency (50–75 nmol/L) were found in 41 and 33% of the population, respectively. In multivariable analysis controlled for confounders, seasonally adjusted 25OHD concentrations were significantly ( p