Calcium supplementation and bone mineral density in adolescent girls

JAMA. 1993 Aug 18;270(7):841-4.


Objective: To evaluate the effect of calcium supplementation on bone acquisition in adolescent white girls.

Design: A randomized, double-blind, placebo-controlled trial of the effect of 18 months of calcium supplementation on bone density and bone mass.

Subjects: Ninety-four girls with a mean age of 11.9 + 0.5 years at study entry.

Setting: University hospital in a small town.

Interventions: Calcium supplementation, 500 mg/d calcium as calcium citrate malate; controls received placebo pills.

Main outcome measures: Bone mineral density and bone mineral content of the lumbar spine and total body were measured by dual-energy x-ray absorptiometry and calcium excretion from 24-hour urine specimens.

Results: Calcium intake from dietary sources averaged 960 mg/d for the entire study group. The supplemented group received, on average, an additional 354 mg/d of calcium. The supplemented group compared with the placebo group had greater increases of lumbar spine bone density (18.7% vs 15.8%; P = .03), lumbar spine bone mineral content (39.4% vs 34.7%; P = .06), total body bone mineral density (9.6% vs 8.3%; P = .05), and 24-hour urinary calcium excretion (90.4 vs 72.9 mg/d; P = .02), respectively.

Conclusions: Increasing daily calcium intake from 80% of the recommended daily allowance to 110% via supplementation with calcium citrate malate resulted in significant increases in total body and spinal bone density in adolescent girls. The increase of 24 g of bone gain per year among the supplemented group translates to an additional 1.3% skeletal mass per year during adolescent growth, which may provide protection against future osteoporotic fracture.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Absorptiometry, Photon
  • Adolescent
  • Anthropometry
  • Bone Density / drug effects*
  • Calcium / administration & dosage
  • Calcium / pharmacology*
  • Calcium / urine
  • Child
  • Double-Blind Method
  • Female
  • Humans
  • Lumbar Vertebrae / drug effects
  • Lumbar Vertebrae / metabolism
  • Nutrition Assessment


  • Calcium