Premenopausal overweight women do not lose bone during moderate weight loss with adequate or higher calcium intake.
BACKGROUND
Weight loss is associated with bone loss, but this has not been examined in overweight premenopausal women.


OBJECTIVE
The aim of this study was to assess whether overweight premenopausal women lose bone with moderate weight loss at recommended or higher than recommended calcium intakes.


METHODS
Overweight premenopausal women [n = 44; x (+/-SD) age: 38 +/- 6.4 y; body mass index (BMI): 27.7 +/- 2.1 kg/m(2)] were randomly assigned to either a normal (1 g/d) or high (1.8 g/d) calcium intake during 6 mo of energy restriction [weight loss (WL) groups] or were recruited for weight maintenance at 1 g Ca/d intake. Regional bone mineral density and content were measured by dual-energy X-ray absorptiometry, and markers of bone turnover were measured before and after weight loss. True fractional calcium absorption (TFCA) was measured at baseline and during caloric restriction by using a dual-stable calcium isotope method.


RESULTS
The WL groups lost 7.2 +/- 3.3% of initial body weight. No significant decrease in BMD or rise in bone turnover was observed with weight loss at normal or high calcium intake. The group that consumed high calcium showed a strong relation (r = 0.71) between increased femoral neck bone mineral density and increased serum 25-hydroxyvitamin D. No significant effect of weight loss on TFCA was observed, and the total calcium absorbed was adequate at 238 +/- 81 and 310 +/- 91 mg/d for the normal- and high-calcium WL groups, respectively.


CONCLUSIONS
Overweight premenopausal women do not lose bone during weight loss at the recommended calcium intake, which may be explained by sufficient amounts of absorbed calcium.
Riedt
Claudia S
CS
Rutgers University, New Brunswick, NJ, USA.
Schlussel
Yvette
Y
von Thun
Nancy
N
Ambia-Sobhan
Hasina
H
Stahl
Theodore
T
Field
M Paul
MP
Sherrell
Robert M
RM
Shapses
Sue A
SA
D015502:Absorptiometry, Photon; D000328:Adult; D001823:Body Composition / Q000502:physiology; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D050071:Bone Density Conservation Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004038:Diet, Reducing; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D010281:Parathyroid Hormone / Q000097:blood; D017697:Premenopause / Q000502:physiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D015431:Weight Loss / Q000502:physiology*
D050071:Bone Density Conservation Agents; D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D