So I've had a blood test that confirms mild deficiency, and I have many of the symptoms of deficiency, but I'm unable to tolerate oral Vitamin D3 above 100-200 IU per day which is puzzling as I don't react at all from my skins Vit D production with sun exposure, even when I've spent a long time in the sun without protection. The symptoms I get from oral supplementation are serotonergic in nature, as Vit D upregulates serotonin production through tryptophan hydroxylase (TPH). I have a history of serotonin toxicity so I am very sensitive to this.
Does anyone know the pathways of Vitamin D well enough to give me any suggestions?
I'm thinking of whether there is anything I can do to hinder its regulation of TPH, or if there is a way to have a slow release of Vitamin D or something that mimics sun-exposure. I've heard of UVB lamps, injections but the doses are usually high, and ergocalciferol (which I haven't tried yet).
I have tried:
NOW Foods D3 liquid (in MCT oil, 100 IU per drop)
Source Naturals D3 400 IU tablets (cut into quarters)
Thanks in advance