Effects of an iron or iron and vitamin D-fortified flavored skim milk on iron metabolism: a randomized controlled double-blind trial in iron-deficient women.
Study Goal
The researchers aimed to determine whether dairy fortified with iron and vitamin D, compared to dairy fortified with iron alone, improves iron metabolism in iron-deficient menstruating women.
Results Summary
Iron-fortified skim milk did not improve iron status, but vitamin D fortification slightly enhanced erythropoiesis and iron status. Serum 25-hydroxyvitamin D levels increased significantly in the Fe + D group compared to the Fe group.
Population
Iron-deficient menstruating women
Effective Dosage
500 mL/day of fortified flavored skim milk
Duration
16 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
iron-fortified flavored skim milk | no change | iron status | iron-deficient menstruating women | - | does not improve | #1 |
iron- and vitamin D-fortified flavored skim milk | increase | serum 25-hydroxyvitamin D | iron-deficient menstruating women | - | significantly increased | #2 |
iron- and vitamin D-fortified flavored skim milk | increase | serum 25-hydroxyvitamin D | iron-deficient menstruating women | - | higher | #3 |
iron- and vitamin D-fortified flavored skim milk | increase | erythrocytes | iron-deficient menstruating women | - | higher values | #4 |
iron- and vitamin D-fortified flavored skim milk | increase | hematocrit | iron-deficient menstruating women | - | higher values | #5 |
iron- and vitamin D-fortified flavored skim milk | increase | hemoglobin | iron-deficient menstruating women | - | higher values | #6 |
iron- and vitamin D-fortified flavored skim milk | increase | erythropoiesis | iron-deficient menstruating women | - | slightly enhances | #7 |
iron- and vitamin D-fortified flavored skim milk | increase | iron status | iron-deficient menstruating women | - | slightly enhances | #8 |
iron-fortified flavored skim milk | increase | calcium intake | iron-deficient menstruating women | - | increased | #9 |
iron-fortified flavored skim milk | increase | iron intake | iron-deficient menstruating women | - | increased | #10 |
iron- and vitamin D-fortified flavored skim milk | increase | calcium intake | iron-deficient menstruating women | - | increased | #11 |
iron- and vitamin D-fortified flavored skim milk | increase | iron intake | iron-deficient menstruating women | - | increased | #12 |
OBJECTIVES: Iron deficiency anemia and vitamin D deficiency are considered global pandemics. The aim of this study was to determine whether the consumption of a dairy product fortified with iron and vitamin D, compared to the equivalent with only added iron, exerts an additional effect on iron metabolism in iron-deficient menstruating women. METHODS: The design was a randomized, placebo-controlled, double-blind, parallel-group trial of 16 weeks' duration. Subjects were randomized into 2 groups that consumed, as part of their usual diet, 500 mL/day of an iron (n = 54) or iron- and vitamin D-fortified (n = 55) flavored skim milk. At baseline and monthly, dietary intake, body weight, and hematological and iron metabolism biomarkers were determined. Serum 25-hydroxyvitamin D was analyzed at baseline and weeks 8 and 16. Data were analyzed by analysis of variance (ANOVA) of repeated measures for time and Time × Group interaction effects. RESULTS: A total of 109 volunteers completed the study. Calcium and iron intakes increased during the intervention (p < 0.001 for both groups). Serum 25-hydroxyvitamin D significantly increased in Fe + D group during the assay (p < 0.001) and at week 16 it was higher compared to the Fe group (p < 0.05). Serum ferritin, serum transferrin, mean corpuscular volume, mean corpuscular hemoglobin, and red blood cell distribution width showed significant time effects but no Time × Group interaction. Higher values of erythrocytes (p = 0.01), hematocrit (p = 0.05), and hemoglobin (p = 0.03) at week 8 were observed in the Fe + D group compared to the Fe group. CONCLUSION: Iron-fortified flavored skim milk does not improve iron status in iron-deficient menstruating women. However, vitamin D fortification slightly enhances erythropoiesis and iron status.