I am merely a layperson/patient with vague anecdotal experiences, but the notion that Vitamin D is capable of complex unexplored interactions is also my belief.

I am merely a layperson/patient with vague anecdotal experiences, but the notion that Vitamin D is capable of complex unexplored interactions is also my belief. For me, occasional doctor-prescribed monthly slow release doses, intended to help counter depression and seasonal-affective-disorder, instead prefaced weeks/months of arguably mild but disturbing effects after each dose. That is, weird abdominal sensations/pressure, weight loss, paranoia/hypochondria and feelings of doom, among other things. Accordingly I eventually went through a slew of tests, including every blood test under the sun and an ultrasound - nothing found, and calcium levels not elevated. It only happened 3 times, and I only got really suspicious on the third occasion, due to the common factor of the Vitamin D dose taken prior - at which point I swiftly and permanently ceased taking it - which was not really enough time to be certain of the cause, but I sure spent some fraught hours researching Vitamin D at the time - which convinced me of it's complex potential, in a similar manner as this article - and ultimately the particular, temporary syndrome I suffered on those occasions (whatever the cause) has not recurred in the years since.