First, you only need oral supplementation if your serum 25-OH-D (bloodtest) reaches below 50 ng/ml or 125 nmol/L.
I would recommend being at, or above 80 ng and 200 nmol.
Second, you need light. Mentally, a full spectrum "white" light into your eyes will help you create serotonin and dopamine. Look for lightbulbs or other forms that create a Full Spectrum light. During dark long winters you might need this addition for your well-being.
Third, you can create additional D-vitamin i tanning beds with UVB (doublecheck this with your tanning bed host). It's not super effective but it can give a very small boost. I personally do it because there's not only D-vitamin created by being exposed to UVB, but also 10+ other chemicals needed for normal functioning.
I wanted to share this with you. A few months back I started a thread when when I got my Vitamin D blood result back which showed I was at a ridiculous low level.
anyway to update you I didn't take the supplements the doctor advised, but instead I went under the sunbed this was 3 months ago, just got my results back and D is now at a normal level.....amazing!!!!!!!!!!!1