title: Vitamin D fortification of milk products does not resolve hypovitaminosis D in young Finnish men.
abstract: OBJECTIVE
  To study if vitamin D fortification of milk products started in February 2003 has improved vitamin D status of young Finnish men, which has been poor before.
  
  
  METHODS
  A longitudinal study of one cohort.
  
  
  METHODS
  Helsinki University Central Hospital.
  
  
  METHODS
  Sixty-five healthy men, studied for the first time in January 2001, were re-examined in January 2004. They were aged 18-21 years in 2001.
  
  
  METHODS
  Blood was sampled for determination of serum 25-hydroxyvitamin D (25-OHD) and intact parathyroid hormone (iPTH). 25-OHD was measured by both radioimmunoassay (RIA) and high-pressure liquid chromatography (HPLC). Consumption of milk, sour milk and fish and use of vitamin D supplements were assessed using a questionnaire.
  
  
  RESULTS
  In January 2004, vitamin D fortification had raised serum 25-OHD level, with the mean of individual percent changes being 20.4% measured with RIA (P=0.0015). The correlation between the RIA and HPLC methods was high (r=0.85). Nineteen men (29.2%) had vitamin D deficiency (25-OHD<or=20 nmol/l) and 48 men (73.8%) had hypovitaminosis D (25-OHD<or=37.5 nmol/l). Serum 25-OHD and iPTH levels correlated inversely (r=-0.30; P=0.017). Serum 25-OHD levels were 52.0% higher for 13 vitamin D supplement users than for 51 non-users (P=0.0001). After exclusion of supplement users, an association between 25-OHD level and consumption of milk products was found (P=0.011), with the median vitamin D level being 6.5 nmol/l higher for those consuming four glasses of milk products or more daily than for those consuming one or less. Likewise, the higher the milk consumption, the higher the difference in 25-OHD between years 2004 and 2001 (P=0.0025).
  
  
  CONCLUSIONS
  Vitamin D fortification of milk products slightly but insufficiently improved the poor vitamin D status of young Finnish men during winter. Further supplementation is warranted in order to normalize vitamin D levels and to support achievement of maximum peak bone mass.
  
  
  BACKGROUND
  Supported by Paulo Foundation, Juho Vainio Foundation, Emil Aaltonen Foundation and Research Funding from Helsinki University Central Hospital (Erityisvaltionosuus).
authors.affiliation: Division of Endocrinology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: V-V
authors.initials: VV
authors.lastname: Välimäki
authors.forename: E
authors.initials: E
authors.lastname: Löyttyniemi
authors.forename: M J
authors.initials: MJ
authors.lastname: Välimäki
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D002136:Calcium, Dietary / Q000008:administration & dosage; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D015331:Cohort Studies; D005387:Finland; D005527:Food, Fortified; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008892:Milk; D010281:Parathyroid Hormone / Q000097:blood*; D011863:Radioimmunoassay; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000178:diet therapy* / Q000453:epidemiology
chemical_list: D050071:Bone Density Conservation Agents; D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D