Sunlight and Vitamin D

I have tested 1,25 (OH) 2 Vitamin D3 and the result is 71,4 pg/mL.
How much is this in nmol/l?
Should I increase?

Sure, it said “pg/ml”, wich would be picogram per milliliter?
In Germany, where I live, the reading is given in ng/ml, and the factor for converting this into nmol/L is 2.5, so that the level recommended by OMS of 150–225 nmol/L (best around 200 nmol/L) translates into 60–90 ng/ml (best around 80 ng/ml).
If your reading were 71.4 ng/ml, I would say: Fine! Within the range we are aiming at!
But a picogram is only the thousandth part of a nanogram (ng), so that 71.4 pg/ml are only 0.0714 ng/ml which would be way too low — i. e. only the thousandth part of what you need.
In my opinion, it is very unlikely that your reading revealed such a catastrophically low level!
Perhaps it was 71.4 pg/nl = picogram per nanoliter? As a nanoliter is the thousandth part of a milliliter, that would be exactly the same as 71.4 ng/ml and therefore = 178.5 nmol/L and fine.
Can you check again?
Best regards
Zoë