Purdue University Graduate School
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Factors Influencing Bariatric Patients’ Level of Compliance with Supplement Recommendations and Bioavailability of Iron Supplement Formulations in Roux-en-Y Gastric Bypass Patients

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posted on 2019-12-06, 15:29 authored by Haley R Snell-SparapanyHaley R Snell-Sparapany

In our first study, we explored the barriers to complying with iron supplement recommendations using focus groups. We recruited adults, ages 18-75 years, who have had bariatric surgery at least two months previously to participate in one of four 90-minute focus groups. Participants filled out a survey asking for information on demographics and supplement use, and a facilitator asked a set of pre-determined questions to each group. Responses were written, recorded, transcribed using TranscribeMe (San Francisco CA), and analyzed using NVivo (QSR International Pty Ltd, Doncaster, Victoria). The focus groups contained nineteen participants, five of which had sleeve gastrectomy (SG) and fourteen had Roux-en-Y gastric bypass (RYGB). The average age of the participants was 49.3 ± 9.4 years, and they had undergone surgery 3.9 ± 3.6 years previously. The key factors that influenced participants’ adherence to supplement guidelines were cost, tolerability, and palatability of the supplement, level of knowledge and support from healthcare providers, and convenience of the supplementation regime.

The second study was a prospective observational study to determine the bioavailability of ASP compared to FS. Iron deficient RYGB patients ages 18-65 years, who had surgery at least 6 months previously, participated in 8-hour iron absorption tests. Participants received a low-iron breakfast with 65 mg ASP (N=7) or FS (N=3). We assessed serum iron every 30 minutes for 8 hours following the supplementation using a colorimetric assay (South Bend Medical Foundation, South Bend, IN). In participants administered FS, serum iron increased 96.0 ± 27.2 µg/dL compared to baseline, whereas with ASP, serum iron increased 5.8 ± 4.7 µg/dL compared to baseline (P = 0.02). These data indicate that ASP is not as bioavailable as FS in RYGB patients.


Degree Type

  • Master of Science


  • Nutrition Science

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Nana Gletsu-Miller

Additional Committee Member 2

Regan Bailey

Additional Committee Member 3

Kathleen Hill Gallant