The response of the retinal vessels to the vitamin D supplementation treatment running title: The retinal vessels and vitamin D supplementation treatment

Although the effects of some confounding factors, such as exposure time to sunlight and dietary vitamin D intake in the study, were not yet known, vitamin D supplementation therapy appeared to affect retinal microvasculature. Optic coherence tomography angiography might indicate noninvasively the effectiveness or sufficiency of vitamin D treatment at the microvascular level, although the observed changes in the retinal vessels are as yet not fully understood.