title: Maternal serum and breast milk vitamin D levels: findings from the Universiti Sains Malaysia Pregnancy Cohort Study.
abstract: BACKGROUND
  Vitamin D deficiency has become a global health issue in pregnant women. This study aimed to assess the adequacy of maternal vitamin D status by measuring maternal serum and breast milk 25-hydroxyvitamin D [25(OH)D] levels and to determine the association between maternal serum and milk 25(OH)D levels.
  
  
  METHODS
  Data was obtained from the Universiti Sains Malaysia Pregnancy Cohort Study. This study was conducted from April 2010 to December 2012 in the state of Kelantan, Malaysia. Blood samples from pregnant women aged 19 to 40 years were drawn in the second and third trimesters of pregnancy, while breast milk samples at delivery, 2, 6 and 12 months postpartum were collected to analyze for 25(OH)D levels. A total of 102 pregnant women were included in the analysis.
  
  
  RESULTS
  Vitamin D deficiency [25(OH)D <50 nmol/L] was detected in 60% and 37% of women in the second and third trimesters of pregnancy, respectively. There were 6% and 23% of women who reached normal level of vitamin D status in the second trimester and the third trimester, respectively. Multivitamin intakes during pregnancy were significantly associated with higher serum 25(OH)D levels in the second trimester (β = 9.16, p = 0.005) and the third trimester (β = 13.65, p = 0.003). 25(OH)D levels in breast milk during the first year of lactation ranged from 1.01 to 1.26 nmol/L. Higher maternal serum 25(OH)D level in the second trimester of pregnancy was associated with an elevated level of 25(OH)D in breast milk at delivery (β = 0.002, p = 0.026).
  
  
  CONCLUSIONS
  This study shows that high proportions of Malay pregnant women are at risk of vitamin D deficiency. Maternal vitamin D status in the second trimester of pregnancy was found to influence vitamin D level in breast milk at delivery.
authors.affiliation: Nutrition Program, School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
authors.forename: Hamid Jan
authors.initials: HJ
authors.lastname: Jan Mohamed
authors.affiliation: Fonterra Co-operative Group Ltd, Palmerston North, New Zealand.
authors.forename: Angela
authors.initials: A
authors.lastname: Rowan
authors.affiliation: Fonterra Research and Development Centre, Palmerston North, New Zealand.
authors.forename: Bertram
authors.initials: B
authors.lastname: Fong
authors.affiliation: Nutrition Program, School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
authors.forename: See-Ling
authors.initials: SL
authors.lastname: Loy
mesh_terms: D015331:Cohort Studies; D005260:Female; D006801:Humans; D007774:Lactation / Q000097:blood; D008895:Milk, Human / Q000378:metabolism*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood*; D011262:Pregnancy Trimester, Second / Q000097:blood*; D011263:Pregnancy Trimester, Third / Q000097:blood*; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood*
chemical_list: D014807:Vitamin D