Comment by bflesch

Also there many are other potential factors such as desk-job, sports, sun exposure, and nutrition.

HOWEVER, there are also birth defects such as the MTHFR gene mutation which reduce Vitamin B12 utilization of your cells by as much as 70%. It has far-reaching consequences for every single cell in your body. Modern medicine is mainly symptom-based and things like chronic Vitamin B12 deficiency are hard to diagnose (unlike famous low Vitamin D levels). In many countries you can't even sequence DNA of your own child, and for a hereditary gene defect in a core chemical reaction of the human metabolism this is just staggering.

For example as someone who has the MTHFR gene defect, my organism needs the "bio-available", methylated version of Vitamin B12, because it can only use 30% of the Vitamin B12 in my bloodstream.

The effects of Vitamin B12 (methylcobalamine) supplementation after many decades of Vitamin B12 deficiency is staggering. Within 30 minutes it felt like someone lifted a very heavy baseball cap off my skull. If someone would've told me methylcobalamin is a potent anti-depressant or some illegal drug I would've believed them based on the effects.

If you scout google scholar or NCBI for recent studies on Vitamin B12 you will find recent case studies that use Vitamin B12 supplementation to treat infertility, long covid symtpoms, and autism in children. And if nature gifts you with the MTHFR gene defect(s), Vitamin B12 can be really rare in your cells.

Yet here we are, even in one of the wealthiest countries in the world you need to do gene sequencing on your own if you want to learn about basic genetic defects, because doctors won't touch anything involving "genes" if the disease is not named after yourself. According to Wikipedia roughly 20-30% of all people have this exact MTHFR defect.

Here is some more info: https://www.snpedia.com/index.php/gs192

PS: ADHD is often linked to depression, and I've been discussing with a good friend what comes first. If you have chronic disease, there is first the disease, then comes the depression. But then doctors or others see you and only focus on the depression which - funnily - increases the depression / anxiety even more.

I wish I knew at a younger age that methylated Vitamin B12 / folate supplementation is needed due to a genetic defect.