It has been experimented that plants do not contain vitamin B12, so individuals who follow a vegetarian diet, especially strict vegetarians who avoid all animal products, may not get enough B12 unless they consume fortified foods or supplements
Foods that may help support healthy glutathione levels include sulfur-rich vegetables such as broccoli, Brussels sprouts, cauliflower, kale, and cabbage
Detoxification Role : The book highlights glutathione's role in detoxifying the body, particularly in the liver, where it helps eliminate harmful substances

Here are some symptoms of undermethylation to look out for: [22] Elevated homocysteine levels Depression Irritability Anxiety Multiple miscarriages Multiple chemical sensitivities Sensitivity to anesthetics Red face that lasts after exercising Allergies Being prone to addiction High libido Obsessive-compulsive disorder (OCD) Low pain threshold Headaches/migraines Digestive problems (such as IBS) Brain fog (especially after protein-rich meals) Insomnia High estrogen levels/estrogen dominance Low energy/fatigue Muscle pain Low levels of neurotransmitters (dopamine, norepinephrine, and serotonin) Heavy menstrual periods with blood clots Flakey skin rash under your nose* Lowered immunity* *Although I havent seen this in the research, its been an observation for me personally, as well as for a few clients, that difficulty fighting off viral infections as well as having a red rash under the nose, seems to correlate with poor methylation