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.
OBJECTIVE
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.


CONCLUSIONS
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.
a Department of Metabolism and Nutrition , Institute of Food Science, Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC) , Madrid , SPAIN.
Laura
L
Toxqui
Ana M
AM
Pérez-Granados
Ruth
R
Blanco-Rojo
Ione
I
Wright
Carmen
C
González-Vizcayno
M Pilar
MP
Vaquero
D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000150:complications* / Q000188:drug therapy; D000818:Animals; D002136:Calcium, Dietary / Q000008:administration & dosage; D004032:Diet; D019587:Dietary Supplements; D004311:Double-Blind Method; D004912:Erythrocytes / Q000378:metabolism; D004920:Erythropoiesis / Q000187:drug effects; D005260:Female; D005527:Food, Fortified; D006400:Hematocrit; D006801:Humans; D007501:Iron / Q000097:blood / Q000494:pharmacology*; D000090463:Iron Deficiencies; D033862:Iron-Binding Proteins / Q000097:blood; D008598:Menstruation; D008892:Milk; D014131:Trace Elements / Q000097:blood / Q000172:deficiency / Q000494:pharmacology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000188:drug therapy; D014815:Vitamins / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D055815:Young Adult
D002136:Calcium, Dietary; D033862:Iron-Binding Proteins; D014131:Trace Elements; D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D007501:Iron