Zinc and Bone Turnover Study in Adolescent Females
Condition: Bone; Growth; Osteoporosis
MeSH terms: Osteoporosis
Study type: Interventional

Summary: 
      The purpose of the study is to determine the effects of zinc supplementation on bone growth
      over four weeks. Participants will agree to attend two visits to our laboratory and at each
      will complete blood and urine samples, questionnaires related to diet and physical activity
      and will receive a bone scan at the first appointment.
    

Detailed description: 
      Significant accomplishments have been achieved with respect to our understanding of calcium
      and vitamin D and skeletal health, yet a body of scientific evidence has also identified
      understudied nutrients that have potential for reducing the burden of osteoporosis. Zinc has
      important roles in bone metabolism and there are indications from animal and human studies
      that beyond correcting skeletal and growth impairments under deficiency conditions,
      supplementation with zinc may have a bone health-promoting role. It has been postulated that
      the action of zinc on bone metabolism is partially mediated by Insulin-like growth factor one
      (IGF-I). Prior to undertaking a long-term bone trial, a short-term zinc supplementation trial
      is proposed to first determine if zinc alters intermediate markers of bone metabolism in
      healthy, early pubertal females (9-10.5 years of age). We hypothesize that healthy females
      receiving 24 mg zinc /day over 4 weeks will have elevated serum markers of bone formation and
      plasma growth factors compared to those receiving placebo. We further hypothesize that the
      differences between the zinc and placebo groups will vary by race. To test these hypotheses,
      we will screen early pubertal females to assure similar maturational status and conduct a
      3-week, randomized, double-blind, placebo-controlled trial with a zinc supplementation (zinc
      sulfate; n=80) and a placebo (n=80) arm. The groups will be further divided by race
      (non-Hispanic White and non-Hispanic Black; n=40 per group). The specific aims are to
      determine if early pubertal females supplemented with zinc compared to those receiving
      placebo will have: 1) greater increases in markers of bone turnover favoring bone formation;
      2) greater increases in plasma IGF-1 and IGFBP-3; and 3) changes in bone turnover markers,
      IGF-1 and IGFBP-3 that differ by race. In addition, anthropometric measures, maturity offset,
      sexual maturation, erythrocyte superoxide dismutase activity, ceruloplasmin, dietary intakes
      and physical activity will be determined. Findings from this study will provide preliminary
      evidence of whether supplementation with zinc is a viable nutrition strategy to improve
      biochemical indices of bone turnover and growth factors in young females. Moreover, the
      results will help determine if a long-term clinical bone trial is warranted to more
      definitely assess the potential for supplemental zinc to reduce the risk for osteoporosis.
    

Intervention name(s): Zinc Sulfate; Placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): 9mg elemental zinc via 23mg zinc sulfate/day; Cellulose pill given as placebo
Intervention MeSH terms: Zinc Sulfate
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Zinc; Bone; Adolescents; Growth