Absorption is poor sublingually and is limited by https://en.m.wikipedia.org/wiki/Intrinsic_factor so I wouldn’t be surprised if most of those doses just get destroyed in the stomach

I have exactly that problem - malabsorption. The sublingual tablets have helped considerably.

I’m just trying to understand why the other commenter considers the dose mention as “high”. I’ve never heard that claimed before.

I was referring to multivitamin levels which are typically ~100% RDA, so to get the levels the study considered harmful, you have to be intentionally taking large doses of B Vitamins which is easy not to do.

Some Caffeine Shots include very high doses of B6 and B12 vitamins.

## 2023-12: B6/B12 RDVs, RDV % Supplement Facts inconsistencies

5-Hour Energy nutrition facts: https://www.google.com/search?q=5+hour+energy+nutrition+fact... :

> B6: 40mg: 2000% RDV

> B12: 500mcg: 8333% RDV

5-Hour Energy Extra Strength:

> B6: 40mg: 2353%

> B12: 500mcg: 20833%

Summit Red Thunder Energy Shot nutrition facts: https://www.google.com/search?q=Summit+Red+Thunder+Energy+Sh...

> Kirkland Signature Extra Strength:

> B6: 40mg: 2533% RDV

> B12: 500mcg: 20833% RDV

...

Again,

/? b6 b12 male smokers https://www.google.com/search?q=b6+b12+male+smokers

"Long-Term, High-Dose Vitamin B6/B12 Use Associated With Increased Lung Cancer Risk Among Men" (2023) https://cancer.osu.edu/news/long-term-high-dose-vitamin-b6-b...