Relationship between vitamin D deficiency, bone remodelling and iron status in iron-deficient young women consuming an iron-fortified food

European Journal of Nutrition, 06/08/2012

Blanco–Rojo R et al. – The prevalence of vitamin D deficiency or insufficiency is very high in iron–deficient women. The recovery of iron status by consuming an iron–fortified food does not affect 25–hydroxyvitamin D levels; however, the increase in iron supply to tissues is lower if the women also present vitamin D deficiency. Although bone health does not seem to be affected in this group of women, correction of iron and vitamin D deficiencies should be promoted in young women to improve present and future health.

Methods

  • Iron biomarkers, 25–hydroxyvitamin D levels and dietary intake were measured in 123 iron–deficient menstruating women.
  • A subgroup (n = 41) participated in a randomised double–blind placebo–controlled study of 16–weeks during winter.
  • They consumed a placebo fruit juice (P) or iron–fortified fruit juice (F).
  • Dietary intake, 25–hydroxyvitamin D, parathormone (PTH), bone alkaline phosphatase (ALP), aminoterminal telopeptide of collagen I (NTX) and iron biomarkers were determined.

Results

  • Ninety–two per cent of the iron–deficient women were vitamin D deficient or insufficient.
  • Transferrin saturation and 25–hydroxyvitamin D were positively correlated. Iron status improved in F, 25–hydroxyvitamin D decreased in F and P, and PTH, ALP and NTX levels were within the normal range and did not vary.
  • Women with 25–hydroxyvitamin D ≥ 50 nmol/L compared with 25–hydroxyvitamin D < 50 nmol/L showed a higher increase in transferrin saturation (a marker of iron supply to tissues) during iron recovery.

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