I take it daily. Doctor was going to tell me about K2 and was surprised when I said I already take it.
I was feeling lethargic and lack energy last winter when I took my annual physical with my PA.
She tested out my Vitamin D level and found my level at 6,
and immediately prescribed Vitamin D for me to take.
My understanding through reading is that K2 enhances the absorption of Vitamin D, making it more effective.
I was aware of Vitamin D possible issues during the winter time
but didn't realize the need for sunshine in areas north of the Mason-Dixon line
since we spend most of the winter time indoors.