In an interview, the researchers state, "the clinical
implications are that vitamin D3 protects the brain through the
immune system and that recommended blood levels of the
25-hydroxy vitamin D3 should be maintained in all seasons
including winter when the sun is not helping to produce vitamin
D in the skin." Brain clearance of amyloid-beta 1-42 (Aβ-42) by
innate immune macrophages (a type of white blood cell) is
required for maintenance of normal brain function. This process
of phagocytosis (the process where one cell engulfs/eats
something) is defective in AD patients. In their latest
laboratory studies, the research team isolated macrophages from
blood samples taken from patients with AD and healthy controls.
They incubated the cells overnight with amyloid-beta, some in
the presence of vitamin D3 and/or curcuminoids. The researchers
observed that vitamin D3 activates a specific chloride channel
that is important in the clearance of Aβ-42 in both types of AD
macrophages (type I and type II). It appears from