There is a new clinical trial D3ForMe that has a big benefit in my eyes: Avoiding the high local vitamin D in the gut Peyers’ Patch after oral supplementation.
Oral supplementation likely affects gut-specific homing leading activated T cells and antibody-secreting cells (ASCs) to both inflamed and non-inflamed regions of the gut. Also antigen recognition may be affected by inhibited DC maturation.
In an earlier vitamin D3 could be safely be delivered through the dermal route.