Effect of 6-Month Vitamin D Supplementation on Plasma Matrix Gla Protein in Older Adults

Nutrients. 2019 Jan 22;11(2):231. doi: 10.3390/nu11020231.

Abstract

Vitamin D supplementation has been widely promoted to restore 25-hydroxyvitamin D concentrations; however, experimental evidence suggests a nutrient interaction with vitamin K. We assessed the effects of 1200 IU vitamin D₃ per day versus placebo for six months on vitamin K status in a randomized, double-blind, placebo-controlled trial with participants aged 60⁻80 years with depressive symptoms and ≥1 functional limitation for a secondary analysis. Stored baseline and six-month follow-up blood samples were available for 131 participants (n = 65 placebo vs. n = 66 vitamin D supplementation). We measured dephosphorylated uncarboxylated matrix gla protein (MGP) (dp-ucMGP) concentrations-a marker of vitamin K deficiency. Mean age was 68 years, and 89 participants (68%) were women. Vitamin K antagonists were used by 16 participants and multivitamin supplements by 50 participants. No differences in change between intervention and placebo were found (-38.5 ± 389 vs. 4.5 ± 127 (pmol/L), p = 0.562). When excluding vitamin K antagonist users and multivitamin users, dp-ucMGP at follow-up was significantly higher in the vitamin D group (n = 40) compared to placebo (n = 30), with a difference of 92.8 (5.7, 180) pmol/L, adjusting for baseline dp-ucMGP and sex. In conclusion, vitamin D supplementation for six months did not affect vitamin K status; however, among participants without vitamin K antagonist or multivitamin use, vitamin D supplementation influenced dp-ucMGP concentrations.

Keywords: randomized controlled trial; vitamin D supplementation; vitamin K status.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Calcium-Binding Proteins / blood*
  • Calcium-Binding Proteins / metabolism
  • Cholecalciferol / administration & dosage
  • Cholecalciferol / pharmacology*
  • Double-Blind Method
  • Extracellular Matrix Proteins / blood*
  • Extracellular Matrix Proteins / metabolism
  • Female
  • Gene Expression Regulation / drug effects
  • Humans
  • Male
  • Matrix Gla Protein
  • Middle Aged

Substances

  • Calcium-Binding Proteins
  • Extracellular Matrix Proteins
  • Cholecalciferol

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