Methods
Study population
The population of the present study consisted of 59 inmates incarcerated at
the Fourth Avenue Maricopa County Jail. All male inmates between the ages of 20
and 41 y who were able to read and write in English were eligible for study inclusion.
Because one of our a priori hypotheses was to compare circulating
25(OH)D concentrations of those who were newly incarcerated with those who
had been at the Fourth Avenue Jail for at least 1 y, we employed two main procedures
for study recruitment. For the newly incarcerated group (group 1), men
within the eligible age range who presented for a health assessment within 2 mo
of incarceration were approached for participation in the study by Maricopa
County Correctional Health Services (MCCHS) staff. For those incarcerated >1 y
(group 2), any eligible inmate who presented for, or requested, a medical
assessment or examination was invited to join the study. When inmates from
either group agreed to participate, the consent process was completed.
Ethics
This study was conducted according to the guidelines laid down in the
Declaration of Helsinki and all procedures involving human subjects were
approved by the University of Arizona Institutional Review Board (Protocol
13-0439) and the MCCHS. Written informed consent was obtained from all
participants. Because the proposed study was conducted within a population
categorized as vulnerable by the Code of Federal Regulations, we followed all
additional procedures required by the University of Arizona Human Subjects
Protection Program. We addressed each of criteria outlined in 45 CFR x46.305,
and thereafter the study and all related procedures were approved by the university’s
Institutional Review Board (Protocol 13-0439) and the MCCHS.
Data collection and study procedures
After the informed consent process was completed, including obtaining
written informed consent from all participants, data regarding age, race, height
and weight, and time of incarceration were collected from each study participant.
Additionally, a single blood draw of 10 cc was obtained from each inmate. These
samples were collected at the initial health assessment for newly incarcerated
inmates, and at the health examination of those inmates who had been in the jail