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
Published: 11 October 2013
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).
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.
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).
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