Though vitamin D can be absorbed via exposure to sunlight and consumption of fortified foods, vitamin D inadequacy remains a prevalent health issue globally.
As such, scientists have been exploring innovative methods to increase vitamin D levels. Researchers from China's Hunan University, the University of Massachusetts, Turkey's Hitit University, and Tufts University in Boston conducted a study to evaluate vitamin D absorption through nanoscale delivery systems.
Delivering the D
Using a simulated gastrointestinal tract system, they assessed the in vitro bio-accessibility of cholecalciferol — or vitamin D3 — in nanoemulsion.
They also examined vitamin D3's in vivo bio-availability by orally administering three groups of mice with either vitamin D3 nanonemulsion, vitamin D3 coarse emulsion, or vehicle nanoemulsion without vitamin D3.
They observed that the nanoemulsion-based delivery system increased vitamin D3's in vitro bio-accessibility by almost four times, and the mouse study showed that the group given vitamin D3 coarse emulsion saw a 36% increase in serum vitamin D levels when compared to the control group.
Additionally, the vitamin D3 nanoemulsion were found to have increased the mice's serum vitamin D levels by 73%.
The researchers wrote that their findings "indicated that a nanoemulsion-based delivery system is a promising approach to improve vitamin D bioavailability, and further studies are warranted to determine its efficacy in humans".
Nanoemulsification markedly improved both in vitro and in vivo vitamin D absorption, as shown by the higher levels of serum vitamin D.
The nanoemulsion also reduced the variation of vitamin D absorption when compared to the coarse emulsion.
The researchers concluded that the enhancement of vitamin D bio-availability and the homogeneity of vitamin D absorption brought about by nanoemulsion would "not only improve vitamin D absorption but also reduce the risk for some individuals being exposed to excess vitamin D".
"Although several limitations exist in (the) study as described above, the results demonstrated that the nanoemulsion has the potential to be utilised as a novel strategy to deliver vitamin D in certain applications, and thereby help to improve vitamin D status, which remains a critical public health issue in our society."
Source: Molecular Nutrition & Food Research
"The Efficacy of Nanoemulsion-Based Delivery to Improve Vitamin D Absorption: Comparison of in Vitro and in Vivo Studies"
Authors: Alagu Selvi Kadappan, et al.