Available at: https://digitalcommons.calpoly.edu/theses/65
Date of Award
MS in Agriculture - Food Science and Nutrition
Food Science and Nutrition
Susan Hawk, PhD, RD
Iron deficiency anemia is the most common nutritional deficiency disease worldwide (Mahan & Escott-Stump, 2004). Iron deficiency anemia is of major concern especially in women of child bearing age and those who follow a vegetarian diet. The objective of this study was to compare the nutrient and hematological values related to iron status in female university students following a vegetarian versus following a nonvegetarian diet. This study took a cross sectional analysis of 39 female students at California Polytechnic State University (Cal Poly State University) in San Luis Obispo, CA. Of the participants 19 were following a vegetarian diet and 20 were following a nonvegetarian diet. To participate, individuals had to be female, current Cal Poly students, and between the ages of 18 and 22 years old. Those taking vitamin or mineral supplements, medications (including oral contraceptives), smokers, and pregnant women were excluded. Characteristic, demographic, and anthropometric data were collected through interview, nutrient intake was accessed by averaging three day food records, and hematological parameters were measured. Statistical analysis used nonparametric techniques including the Mann-Whitney Wilcoxon statistical test for demographics and baseline characteristics, the Spearman Rank Correlation analysis and Fisher’s Exact statistical test for associations between vegetarians and nonvegetarians. Results found no significant difference in iron intake between vegetarians and nonvegetarians, however nonvegetarians had higher mean intakes of iron at 16.82 (SD 6.36) mg/day compared to vegetarians at 14.84 (SD 7.10) mg/day (p=0.482). A similar percentage of vegetarians at 66.7% (n=8) compared to nonvegetarians at 65% (n=13) were under the Recommended Daily Allowance (18 mg per day for females 19 to 30 years of age) for mean iron consumption. There were slightly more nonvegetarians at 10% (n=2) compared to vegetarians at 8.3% (n=1) under the Estimated Average Requirement (8.1 mg/day for females 19 to 30 years of age) for mean iron intake. No significant difference was found for serum iron, serum ferritin, transferrin saturation, and total iron binding capacity between vegetarians and nonvegetarians. Finding revealed serum ferritin, the most common iron status indicator, was lower for vegetarians at 23.16 (SD15.54) ng/mL compared to nonvegetarians at 27.75 (SD 18.01) ng/mL (p=0.47). When looking at the stages of iron balance, there was greater percentage of vegetarians with hematological results (serum iron <40 µg/dL, total iron binging capacity of >410 µg/dL, transferrin saturation <15%, and serum ferritin <10 ng/mL) indicating iron deficiency anemia or stage IV negative iron balance compared to nonvegetarians. There was no significant correlation between iron intake and serum ferritin, however results showed a positive association (r=0.28, p=0.09). In conclusion, vegetarian participants are believed to be at higher risk of developing negative iron balance compared to nonvegetarians due to lower iron consumption and lower serum ferritin concentrations. Female university students following a vegetarian diet should be educated on iron deficiency anemia and prevention of iron depletion.