title: Calcium Supplementation Does Not Contribute to Constipation in Healthy Women.
abstract: It is commonly suggested that calcium supplementation contributes to constipation; however, little research has explored the effects of calcium supplementation on gut motility.
  
  
  
  In an 8-week, randomized, double-blind, crossover pilot study, healthy females (n = 27, aged 43.0 ± 10.6 years) received a split dose of 500 mg/d of elemental calcium from calcium carbonate or calcium phosphate each for 2 weeks, after a 2-week baseline and separated by a 2-week washout. Participants completed daily questionnaires of stool frequency, Bristol Stool Form Scale (BSFS), and supplement intake compliance.
  
  
  
  There were no differences among periods. Mean ± SE stool frequency averaged 1.3 ± 0.1 stools/d in each period. Participants reported 34%, 34%, 37%, and 29% of stools were indicative of slow transit or constipation (BSFS of 1 or 2) during baseline, calcium carbonate, calcium phosphate, and washout periods, respectively. Participants also reported from 6% to 10% of stools as fast transit or diarrhea (BSFS of 6 or 7) during the periods.
  
  
  
  This study suggests that neither calcium carbonate nor calcium phosphate, providing 500 mg/d of calcium, affects stool frequency or form. Although stool frequency was normal, the healthy females participating in the study experienced stools indicating slow (constipation) and fast (diarrhea) transit.
authors.affiliation: a Food Science and Human Nutrition Department, University of Florida, Gainesville, FL.
authors.forename: Zainab
authors.initials: Z
authors.lastname: Alyousif
authors.affiliation: a Food Science and Human Nutrition Department, University of Florida, Gainesville, FL.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Ford
authors.affiliation: a Food Science and Human Nutrition Department, University of Florida, Gainesville, FL.
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Dahl
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002119:Calcium Carbonate / Q000008:administration & dosage / Q000009:adverse effects; D002130:Calcium Phosphates / Q000008:administration & dosage / Q000009:adverse effects; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000009:adverse effects*; D003248:Constipation / Q000175:diagnosis* / Q000209:etiology; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005243:Feces / Q000737:chemistry; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D011795:Surveys and Questionnaires
chemical_list: D002130:Calcium Phosphates; D002136:Calcium, Dietary; C020243:calcium phosphate; D002119:Calcium Carbonate