Therapeutic vitamin delivery: Chemical and physical methods with future directions

Vitamins are a diverse group of "life nourishing" molecules that are essential for proper childhood development, and for maintaining health throughout adulthood into old age. Vitamin supplementation is an important strategy for reducing the severe and chronic effects of malnutrition in subsets of the population of the developing world. Additionally, the precise role of many vitamins in certain conditions, including cancer and cardiovascular disease, remains an area of active research, although guidelines for vitamin supplementation in otherwise adequately nourished populations remain controversial. This review describes vitamin delivery methods and techniques, focusing on the most recent advances and novel approaches. Specific attention has been given to physical methods and novel formulations for delivery with an emphasis on reporting pros and cons of each technique and highlighting future directions. Of particular interest is the potential for transdermal delivery of certain vitamins, which is an approach that may provide advantages in some populations (e.g. for vitamin D), but that still requires considerable additional research and clinical validation.