My adult son was on Buspar.

I've never taken vitamins above the level indicated on the label (unless instructed to by a doctor).

I take phenytoin for a seizure disorder (not grand mal) and phenytoin is known to reduce Vitamin D in the body. Yearly, I'd get what appeared to be Seasonal Affective Disorder, a depression that occurred during the winter months.

""Vitamin D can come from one of three sources: sunlight exposure to uncovered skin, overt-the-counter (OTC) vitamin D supplements, and through foods.""

So, I started taking a single 2000 IU (International Units) Softcaps daily, year round, and I no longer get the winter depression. My former neurologist retired, the new one readily agreed about taking the Vitamin D3 (she's not young, it's not like this is a new finding) and she ordered blood tests to be sure I was taking enough, which I am.

Patients should talk to their doctor before taking vitamin supplements, and talking to their pharmacist about medications they take, and the effects supplements may have on the medication, or vice versa, is advised.

From a health site, the following:

""Based on current research, it seems that consuming 1,000–4,000 IU (25–100 mcg) of vitamin D daily should be ideal for most people to reach healthy vitamin D blood levels.

However, don’t consume more than 4,000 IU of vitamin D without your doctor's permission. It exceeds the safe upper limits of intake and is not linked to more health benefits.""

Hope this is of some help.