I use an app called D-Minder to check / control my sun exposure. In the summer months I easily get 5000 IU after a 30 min session in the noon sun, approx 12pm.

I use an app called D-Minder to check / control my sun exposure. In the summer months I easily get 5000 IU after a 30 min session in the noon sun, approx 12pm. Anecdotally vitamin-D does help with my auto-immune, because I need to take much less thyroid dosage (25mcg as opposed to 75mcg) to arrive at the same TSH levels. Higher D levels did make my teeth sensitive so I upped my Calcium and Magnesium levels. I take CCM, calcium citrate malate which is absorbed more easily than calcium carbonate. I also take Vitamin K2 as MK7 and drink Kefir regularly.