The efficacy of dairy products fortified with nano-encapsulated vitamin D3 on physical and mental aspects of the health in obese subjects; the protocol of the SUVINA trial

Background

Vitamin D deficiency is now very common globally. Although ultraviolet B (UVB) light dermal exposure is an important endogenous source of vitamin D, dietary supplementation and routine food fortification are of benefit for increasing serum 25-hydroxyvitamin D [25(OH)D]. However, there remains a high prevalence of vitamin D deficiency (~40 in Europe and 62% in Iran). We have designed a two-phase study including the production of nano-encapsulated vitamin D3, an assessment of its stability after fortifying dairy products, and a human trial evaluating the effects of fortified dairy products on the physical and mental health of participants.

Methods

and design: We established the optimal nanocapsule structure for vitamin D fortification of the various dairy products. The second phase of the study was performed as a ten-week, quadruple-blind randomized controlled trial, where milk and yogurt were fortified with vitamin D-containing nano-capsules, with active and control products being distributed to adult participants living in the City of Mashhad.

Preliminary results

Among 346 subjects who intended to participate in our study, 306 participants were selected according to inclusion criteria. At the end of the trial, seventeen subjects were excluded (with a dropout rate of 5.5%). The mean age of the eligible participants was 41.82 ± 7.81 (51.8% being women). Waist circumferences were 102.59 ± 7.74 and 89.39 ± 7.0 for men and women, respectively. There were no significant differences for weight, waist circumference, BMI, energy intake, and physical activity between the four groups at baseline assessments.

Discussion

This study will be the first RCT determining the efficacy of vitamin D fortification in dairy products using nano encapsulation technology on several aspects of physical and mental health. The sample size and high quality of methodology of this study demonstrate the feasibility and benefits of nanotechnology in the food fortification industry and general health in the population.

The trial registration details

registry name: The National Institute for Medical Research Development (NIMAD), registration number: IRCT20101130005280N27, date of registration: 3.9.2018 and the trial was prospectively registered.