A randomized controlled study of effects of dietary magnesium oxide supplementation on bone mineral content in healthy girls.
BACKGROUND
The role of magnesium (Mg) as a determinant of bone mass has not been extensively explored. Limited studies suggest that dietary Mg intake and bone mineral density are correlated in adults, but no data from interventional studies in children and adolescents are available.


OBJECTIVE
We sought to determine whether Mg supplementation in periadolescent girls enhances accrual of bone mass.


METHODS
We carried out a prospective, placebo-controlled, randomized, one-year double-blind trial of Mg supplementation.


METHODS
The study was conducted in the Clinical Research Centers at Yale University School of Medicine.


METHODS
Healthy 8- to 14-yr-old Caucasian girls were recruited from community pediatricians' offices. Dietary diaries from over 120 volunteers were analyzed, and those with dietary Mg intake of less than 220 mg/d were invited to participate in the intervention.


METHODS
Magnesium (300 mg elemental Mg per day in two divided doses) or placebo was given orally for 12 months.


METHODS
The primary outcome measure was interval change in bone mineral content (BMC) of the total hip, femoral neck, Ward's area, and lumbar spine (L1-L4) after 12 months of Mg supplementation.


RESULTS
Significantly increased accrual (P = 0.05) in integrated hip BMC occurred in the Mg-supplemented vs. placebo group. Trends for a positive Mg effect were evident in the pre- and early puberty and in mid-late puberty. Lumbar spinal BMC accrual was slightly (but not significantly) greater in the Mg-treated group. Compliance was excellent; 73% of capsules were ingested as inferred by pill counts. Serum mineral levels, calciotropic hormones, and bone markers were similar between groups.


CONCLUSIONS
Oral Mg oxide capsules are safe and well tolerated. A positive effect of Mg supplementation on integrated hip BMC was evident in this small cohort.
Carpenter
Thomas O
TO
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8064, USA. thomas.carpenter@yale.edu
DeLucia
Maria C
MC
Zhang
Jane Hongyuan
JH
Bejnerowicz
Gina
G
Tartamella
Lisa
L
Dziura
James
J
Petersen
Kitt Falk
KF
Befroy
Douglas
D
Cohen
Dorothy
D
D000284:Administration, Oral; D000293:Adolescent; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects; D002648:Child; D019587:Dietary Supplements / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008277:Magnesium Oxide / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D010349:Patient Compliance; D010919:Placebos
D010919:Placebos; D008277:Magnesium Oxide