This isn’t specifically a keto question per se, but I am wondering about the absorption of sublingual vitamins. I usually don’t eat until later in the day and there are some supplements like vitamin D that are supposed to be taken with your fattiest meal. Vitamin D is energizing to me so I don’t want to take it too late in the day. Looking at sublingual vitamins D and B12 the instructions always reference taking with a meal. Does this really matter since you are absorbing through your blood vessels under your tongue?
Sublingual vitamin absorption
It does matter. Some medications are potentiated by being taken with food and will not work right if taken on an empty stomach. Others can damage the stomach lining, if food is not present to stimulate the secretion of protective mucus. Vitamins, especially those two, would fall in the former category. Even though some of the vitamins may enter your bloodstream directly (not likely in the case of fat-soluble vitamins), the majority will be swallowed with your saliva, to be absorbed through the stomach lining. Too bad you can’t get enough D and B-12 in your diet to do away with the supplements. Vitamins are known to be much more potent when consumed as part of the foods in which they are found.
If the vitamins are still going through your digestive system then why even bother with a sublingual form?