When it comes to vit B I have had sucess with it but also frightening side effects (palpitations, sleeplessness)when I took to much.
I have tried the natural ones like bee pollen, but this doesnt do it for me. A combination of B complex and superfoods/good diet has worked the best for me as long as I dont overdo the B complex.
The one my body seems to tolerate best is Now foods liquid vit B12 (with all the others Bs)
I recently cut down on the Bs just for a test; and took 1-2 teaspoons of bee pollen daily. After a couple of months the adrenal fatigue symptoms came creeping back (dizziness, allergy/sneezing) After just a few days on the Now vit B the symptoms were gone.