title: Impact of molecularly defined hypolactasia, self-perceived milk intolerance and milk consumption on bone mineral density in a population sample in Northern Europe.
abstract: OBJECTIVE
  Milk intake as a source of calcium is considered an important factor for bone mineral metabolism. Low lactase activity in adult-type hypolactasia (HL) and self-perceived lactose intolerance (LI) are the main limiting factors of milk intake. The aim of this study was to examine the relationship of HL, LI, individual milk consumption and bone mineral density in a population with high milk consumption and a prevalent vitamin D deficiency.
  
  
  METHODS
  A population-based study of 367 men and women aged 25-70 years was conducted in Estonia. HL was diagnosed by direct sequencing of the LCT gene, bone mineral density and body composition measured by dual energy X-ray absorptiometry (DXA). An original health questionnaire was used to collect data on milk and dairy consumption, self-perceived milk intolerance, supplement usage and fracture history.
  
  
  RESULTS
  Lactase genotype and phenotype had no effect on bone mineral density in this high milk consumption population with a prevalent vitamin D insufficiency. Milk consumption was a significant determinant of bone mineral density in Estonia. Self-perceived milk intolerance leads to self-imposed reductions in milk consumption, increases in bone turnover and an increased risk of fracture.
  
  
  CONCLUSIONS
  Self-perceived milk-intolerance rather than HL influences milk consumption and has deleterious effects on bone metabolism.
authors.affiliation: Department of Internal Medicine, University of Tartu, Tartu, Estonia. mart.kull2@kliinikum.ee
authors.forename: Mart
authors.initials: M
authors.lastname: Kull
authors.forename: Riina
authors.initials: R
authors.lastname: Kallikorm
authors.forename: Margus
authors.initials: M
authors.lastname: Lember
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D015519:Bone Density / Q000235:genetics*; D015331:Cohort Studies; D004957:Estonia; D005247:Feeding Behavior; D005260:Female; D005838:Genotype; D006801:Humans; D043322:Lactase / Q000172:deficiency / Q000235:genetics*; D007787:Lactose Intolerance / Q000453:epidemiology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D008892:Milk; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000523:psychology
chemical_list: D043322:Lactase