VB: data analysis, supervision, drafting of the manuscript; FP statistical expertise, drafting of the manuscript CS: study conception and design, drafting of the manuscript; MS: study conception and design, data collection; TB: study conception, supervision; CB: intellectual content, drafting of the manuscript; AB: statistical expertise, data interpretation and supervision.
RT, BR and BKD contributed to the design, data interpretation, work supervision and critical revision of the manuscript.
RT performed all routine tests including measurement of vitamin D. RT, BR and BKD made a contribution in the design, data interpretation, work supervision and critically revising the manuscript.
BJBG carried out data interpretation and statistical supervision.
TW, JIP and KL participated in data interpretation and made supervision of the study.
SR, co-ordination and design of the study, data analysis and interpretation, supervision of experimental work, writing of manuscript.
RC participated in acquisition of patients' data, interpretation of results and supervision of the manuscript.
KRM – Fund acquisition, supervision, data interpretation, manuscript preparation, and final review.
SNF – Study conception, fund acquisition, supervision, data interpretation, manuscript preparation, and final review.
AVA participated in acquisition of patients' data, interpretation of results and supervision of the manuscript.
