Once the informed consent is obtained and the schedule is set with the participant, the
participant will pick up their zinc bottle they will consume for the first two weeks and will
start the study on the scheduled date.
Visit 1 (Week 1, Day 1): The participants will come to Morgan Hall fasting for their first
blood draw visit. They will come to the clinic after an 8-hour fast and we will collect a
blood sample. They will be instructed to take their zinc starting on day 2 every morning
thirty minutes prior to having their regular breakfast and to write what they eat for
breakfast in their breakfast log daily. They will take the given zinc for thirteen days (days
2-14).
Visit 2 (Week 2, Day 15): The participants will come to Morgan Hall after an 8-hour fast and
the investigators will collect a second blood sample. Subjects will then be given
instructions for visits three and four which will take place two weeks later to allow for a
washout period between the crossover studies.
Visit 3 (Week 5, Day 1): The participants will come to Morgan Hall fasting for their third
blood draw visit. They will come to the clinic after an 8-hour fast and the investigators
will collect a blood sample. Subjects will be instructed to take the alternate zinc starting
on day 2 every morning thirty minutes prior to having their regular breakfast and to record
their breakfast in their breakfast log daily. They will take the given zinc for thirteen days
(days 2-14).
Visit 4: (Week 6, Day 15): The participants will come to Morgan Hall after an 8-hour fast and
the investigators will collect a final fourth blood sample. The subjects' breakfast logs will
be collected at this time and their participation in the study will be completed.
Study diets:
Study subjects will receive a total of 26 days of zinc (13 days of one form prior to the
washout period, and then 13 of the alternate form after). They will be provided with 13 days
of zinc 30 mg zinc, as zinc gluconate, and 30 mg zinc, as a zinc amino acid complex, per day.
They will be randomly assigned to which form of zinc they will take for the first two weeks,
taking either zinc gluconate or zinc amino acid in a fasted state. All participants will be
asked to take the zinc in the fasted state at least 30 minutes before their breakfast meal.
The men will log their breakfast foods, the amounts consumed, and the time they ate breakfast
every day. They will be asked to maintain a steady dietary pattern over the course of the two
weeks as well as maintain a steady physical activity routine.
Fasting:
No food is allowed for an 8-hour period before any of the 4 visits requiring blood sampling.
Water can and should be consumed during the fast to maintain hydration and to facilitate
blood collection. Any other beverages besides water are not to be consumed during the fasting
period.
Blood samples (week 1, day 1; week 2, day 15; week 5, day 1; week 6, day 15.) Participants
will provide a total of 4 blood samples during the study. The blood sample will be drawn by
inserting a needle into a vein in their arm. Each sample will be approximately 15 ml (or 1
tablespoon); a total of 60 ml (about 1/4 cup) will be drawn for the whole study.
Laboratory analysis of samples. Blood samples will be analyzed for their total zinc content
by inductively coupled plasma - optical emission spectrometry (ICP-OES) and for FADS1
activity index along with other fatty acids by liquid chromatography with tandem mass
spectrometry (LC-MS/MS).