Reports that inadequate dietary calcium intake may contribute to age-related bone loss as well as hypertension have prompted the use of calcium supplements for both prevention and therapeutic purposes. However, the role of calcium in age-related bone loss is controversial. Several studies have shown an antagonistic interaction between calcium and iron in humans and between calcium and both iron and magnesium in animals. / The present double-blind, placebo-controlled, randomized study examined the effects of calcium supplementation for 12 weeks on iron and magnesium status of a group of adult, premenopausal women. Measures of iron status included hematocrit, hemoglobin, serum iron, serum ferritin, and total iron binding capacity; serum calcium and serum magnesium were used to determine calcium and magnesium status. / Thirty-five women, average age 30, were randomly assigned to the calcium supplement or placebo group. The calcium group was given 1000 mg of calcium carbonate to be taken with each of two meals (500 mg at each meal); the control group received a placebo also to be taken with each of two meals. Urinary 24-hour calcium was measured as a test of subjects' compliance. / Average intakes of RDA nutrients showed no significant differences between groups except for thiamin and vitamin C; intakes of these nutrients were greater in the calcium group. Only two covariance responses, ferritin and urinary calcium, showed a significant difference between the two groups' laboratory measures after adjustment for pre-values. A significant drop in ferritin occurred after 12 weeks of calcium supplementation in the calcium group compared to the placebo group (29.83 vs 40.53 ng/ml, p $<$ 0.0001). Post 24-hour urinary calcium values were greater in the calcium group (12.63 vs 9.58 mg/dL, p $<$ 0.0001). / These results suggest that regular use of calcium carbonate supplements with meals makes it difficult for women to maintain iron stores. Iron status may need to be monitored closely in people taking calcium supplements. / Source: Dissertation Abstracts International, Volume: 53-03, Section: B, page: 1296. / Major Professor: Nancy Green. / Thesis (Ph.D.)--The Florida State University, 1992.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76628 |
| Contributors | Boyle, Marie Ann., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 129 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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