title: Correlation between 25-hydroxyvitamin D levels and latitude in Brazilian postmenopausal women: from the Arzoxifene Generations Trial.
abstract: CONCLUSIONS
  We investigated vitamin D status in Brazilian cities located at different latitudes. Insufficiency (<50 nmol/L) was common (17 %), even in those living in a tropical climate. Vitamin D insufficiency increased as a function of latitude. Mean 25-hydroxyvitamin D (25(OH)D) levels in each site and latitude correlation were very high (r = -0.88; p=0.02). [corrected].
  
  
  BACKGROUND
  Inadequate vitamin D, determined by low levels of 25(OH)D, has become very common despite the availability of sunlight at some latitudes. National data from a country that spans a wide range of latitudes would help to determine to what extent latitude or other factors are responsible for vitamin D deficiency. We investigated vitamin D status in cities located at different latitudes in Brazil, a large continental country.
  
  
  METHODS
  The source is the Brazilian database from the Generations Trial (1,933 osteopenic or osteoporotic postmenopausal women (60 to 85 years old) with 25(OH)D measurements). 25(OH)D below 25 nmol/L (10 ng/mL) was an exclusion criterion. Baseline values were between fall and winter. The sites included Recife, Salvador, Rio de Janeiro, São Paulo, Curitiba, and Porto Alegre. Mean and standard deviation of 25(OH)D, age, spine and femoral neck T-score, calcium, creatinine, and alkaline phosphatase were calculated for each city. Pearson correlation was used for 25(OH)D and latitude.
  
  
  RESULTS
  Insufficiency (<50 or <20 ng/mL) was common (329 subjects, 17 %). Vitamin D insufficiency increased as a function of latitude, reaching 24.5 % in the southernmost city, Porto Alegre. The correlation between mean 25(OH)D levels in each site and latitude was very high (r = -0.88, p < 0.0001).
  
  
  CONCLUSIONS
  There is a high percentage of individuals with vitamin D insufficiency in Brazil, even in cities near the equator, and this percentage progressively increases with more southern latitudes.
authors: Bone and Mineral Unit, Division of Endocrinology, São Paulo Federal University, São Paulo, Brazil, henriqueparantes@yahoo.com.br.
authors: H P
authors: HP
authors: Arantes
authors: C A M
authors: CA
authors: Kulak
authors: C E
authors: CE
authors: Fernandes
authors: C
authors: C
authors: Zerbini
authors: F
authors: F
authors: Bandeira
authors: I C
authors: IC
authors: Barbosa
authors: J C T
authors: JC
authors: Brenol
authors: L A
authors: LA
authors: Russo
authors: V C
authors: VC
authors: Borba
authors: A Y
authors: AY
authors: Chiang
authors: J P
authors: JP
authors: Bilezikian
authors: M
authors: M
authors: Lazaretti-Castro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000097:blood; D017698:Postmenopause / Q000097:blood*; D015995:Prevalence; D012880:Skin Pigmentation; D013472:Sunlight; D014504:Urban Health / Q000706:statistics & numerical data; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
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