glutathione classification of antioxidants with examples. The figure shows an Glutathione in K-Beauty for Brightening

Pre and postnatal nutritional histories influence reproductive maturation and ovarian function in the rat

Your glutathione system cant renew properly if you dont get enough rest, which makes it less effective

Thats not to say vitamin B12 isnt important

We have lots more on this subject:

Within a day Fatigue lessens (although this can sometimes take some weeks) Become more sociable Mood improvements Better quality of sleep Within a week Brain fog lifts Numbness and pins and needles start to remit Within 2 weeks Strength may return to muscles and joints Within a month Pains in hands and feet remit Strength and grip improve Cyclical hormones such as fertility cycles normalise Thyroid and cortisol hormones normalise ** These results cannot be guaranteed, and can depend on your other lifestyle factors such as diet, sleep health, alcohol / drug intake etc