One of the perennial topics of this blog is the synergy between vitamins A and D. A new Japanese study published last July in the journal Immunology Letters (1) provides further evidence of this synergy, this time suggesting the dynamic duo can courageously combat the most flagellant of our inner impulses, keeping our wayward neutrophils in check and barring them from wandering too far down the winding road that leads to autoimmunity.
These investigators faced a conundrum. A number of studies suggest that the activated hormone form of vitamin D, calcitriol, has great promise for preventing and treating autoimmune diseases, but its usefulness in the clinical setting is currently limited because it promotes excessive accumulation of calcium in the blood and soft tissues. One hardly wants to cure, say, psoriasis if it means having to pass kidney stones.