Background: Vitamin D is critical for skeletal health and is increasingly associated with other pathologies encompassing gastrointestinal, immunological, psychological effects. A significant proportion of the population exhibit suboptimal levels of vitamin D, particularly in Northern latitudes in winter. Supplementation is advocated, but few data are available on achievable or typical rates of change. There has been considerable interest in the potential use of sublingual sprays for delivery of nutrient supplements, but data on efficacy remains sparse.
Methods: A randomised, placebo-controlled, 3-arm parallel design study was conducted in healthy volunteers (n=75) to compare the rate of change of vitamin D status in response to vitamin D3 (3000IU/day) supplementation in capsule and sublingual spray preparations over a six-week period between January and April 2017. Blood 25(OH)D concentrations were measured after day 0, 3, 7, 14, 21 and 42 days of supplementation with 3000IU per diem.
Results: Baseline measurements show 25(OH)D deficiency (<30nmol/l), insufficiency (31-46nmol/l) and sufficiency (>50mmol/l) in 14.9%, 44.6% and 40.5% of the participants respectively. There was a significant elevation in blood concentrations of 25(OH)D in both of the treatment arms (capsule p=0.003, spray p=0.001) compared to control. The capsule and spray were equally efficacious. The rate of change ranged from 0.69-3.93 (capsule) and 0.64-3.34 (spray) nmol/L day with average change in blood 25(OH)D levels of 2 nmol/l/day. Rates followed a simple normal distribution in the study population (ks= 0.94 and 0.82 for capsule and spray respectively). The data suggest that rates of change are higher in individuals with lower levels of 25(OH)D.
Conclusions: A sublingual vitamin D spray is an effective mode of delivery for supplementation in a healthy population. The data provide reference values and ranges for the rate of change of 25(OH)D for nutrikinetic analyses.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)