# Exploring Vitamin D Synthesis and Function in Cardiovascular Health: A Narrative Review
## 6 The Impact of Processing on Vitamin D Levels in Foods and Mitigation Strategies
### Mitigation Strategies to Improve Vitamin D Content in Processed Foods
#### 6.2.4 Encapsulation
demonstrated that Vitamin D3 encapsulated in nanoemulsions showed a 50% improvement in bioavailability compared to non-encapsulated forms. This improvement is attributed to the enhanced solubility and protection against degradation mechanisms provided by the nanoemulsion [127]. Furthermore, the protective capability of nanoemulsions against oxidative degradation is remarkable. A study by [PERSON] et al. [128] found that Vitamin D3 stability increased by up to 70% when encapsulated in nanoemulsions compared to its stability in conventional emulsions under similar conditions. Enhancing the stability of Vitamin D3 is vital for prolonging the shelf life of fortified processed foods, guaranteeing its effectiveness from the moment of production through to the point of consumption. In addition, [PERSON] et al. (2016) focused on the enhancement of Vitamin D3's physicochemical stability and in vitro bioaccessibility using corn protein hydrolysate as a novel nano-vehicle, showcasing innovative approaches to maintaining Vitamin D3's stability against UV light [129]. Controlled release is another significant benefit offered by nanoemulsion technology. According to [PERSON] et al. [130], nanoemulsions can be engineered to release encapsulated nutrients in response to specific triggers, such as pH changes or enzymatic action in the gastrointestinal tract. This targeted release mechanism can lead to a more efficient absorption and utilization of Vitamin D3, potentially enhancing its health benefits. Moreover, the development of ovalbumin-pectin nanocomplexes for Vitamin D3 encapsulation showed enhanced storage stability and sustained release in simulated gastrointestinal digestion. The encapsulation efficiency reached up to 96.37%, with a significant improvement in storage stability and a controlled release profile in simulated intestinal fluid, demonstrating that protein-polysaccharide complexes can effectively encapsulate Vitamin D3 for improved bioavailability [131]. Among the innovative strategies for improving Vitamin D3 stability, the nanostructured Lipid Carriers (NLCs) has been shown to provide a controlled release mechanism in simulated gastrointestinal fluids, increasing oral bioavailability and providing a promising strategy for delivering lipophilic vitamins like Vitamin D3. [PERSON] et al. [132] examined the release profile of Vitamin D3 from NLCs in simulated gastrointestinal fluids, representing the stomach and intestinal environments. The results showed that NLCs could remain stable and protect Vitamin D3 in simulated stomach fluid, releasing more than 90% of the encapsulated Vitamin D3 upon reaching simulated intestinal fluid. Additionally, [PERSON] et al., 2018 focused on chitosan-coated NLCs for Vitamin D loading and studied their physical stability, indicating that coating NLCs with chitosan could effectively stabilize Vitamin D3, preventing its degradation in simulated gastric fluids [133]. Despite these promising outcomes, challenges remain. Concerns about the long-term stability of nanoemulsions and potential impacts on the sensory attributes of fortified foodsneed to be addressed. Furthermore, the safety and regulatory aspects of nanotechnology in food products warrant careful consideration. For instance, comprehensive toxicological assessments are essential to ensure consumer safety. The European Food Safety Authority (EFSA) and the Food and Drug Administration (FDA) are actively working on establishing guidelines for the use of nanotechnology in food products [134; 135]. In conclusion, the incorporation of nanoemulsion technology in food fortification strategies presents a promising approach to improving the stability and bioavailability of Vitamin D3 in processed foods. However, overcoming the technological and regulatory challenges will be crucial for the successful application of this technology. Ongoing research and innovation in this field are essential to unlock the full potential of nanoemulsions for Vitamin D3 fortification and to contribute significantly to addressing nutritional deficiencies.