Three-year follow-up of serum 25-hydroxyvitamin D,parathyroid hormone, and bone mineral density in nursing home residents who had received 12 months of daily bread fortification with 125 mug of vitamin D3

The need for vitamin D3 in the body is well established. What this study points out is that while vitamin d has a long lasting effect in the body when we get enough of it. When we don’t, it can lead to  serious issues including lower bone density.  At this stage, the corrective measures are vitamin d supplementation.

Veronica Mocanu and Reinhold ViethNutrition News Vitamin D

Abstract (provisional)

Background

We conducted a single-arm clinical trial in institutionalized seniors, on the effects of high-dose vitamin D3-fortified bread daily intake (clinicaltrials.gov registration NCT00789503).

Methods

At 1 and 3 years after the dietary fortification was stopped, serum 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH) and bone mineral density were measured in 23 of the original study subjects, aged 60-82 years who had consumed bread buns (100?g) fortified with 320?mg elemental calcium and 125??g (5,000?IU) vitamin D3 daily for one year.

Results

At the end of the 1-year supplementation phase (receiving vitamin D3 fortified bread daily), mean (SD) serum 25(OH)D was 127.3???37.8?nmol/L (baseline for this follow-up).

  • At 1-year follow-up, the serum 25(OH)D was 64.9???24.8?nmol/L (p?=?0.001, vs. baseline); and
  • at 3-year follow-up it was 28.0???15.0?nmol/L (p?=?0.001 vs. baseline). Serum PTH was 18.8???15.6?pg/ml at baseline while
  • at Year 3 it was 48.4???18.4?pg/ml (p?=?0.001 vs. baseline). Lumbar spine BMD did not change from baseline to Year 3. However, by Year 3, hip BMD had decreased (0.927???0.130?g/cm2 vs. 0.907???0.121?g/cm2, p?=?0.024).

Conclusion

Vitamin D nutritional status exhibits a long half-life in the body, and a true steady-state plateau may not even be reached 1year after a discontinuation in dose.

Furthermore, once the need for vitamin D has been established, based on a low baseline serum 25(OH)D concentrations, the appropriate action is to maintain corrective vitamin D supplementation over the long term.

Trial registration Clinical trial registration number: NCT00789503