Vitamin B-12 is a water-soluble vitamin. This means it dissolves in water and is easily absorbed by the body. Normally, water-soluble vitamins are not stored in the body, but vitamin B-12 is the exception. Vitamin B12 lozenges are absorbed through the mucous membranes in the mouth and in the stomach as saliva is swallowed. Whether taken as a pill, lozenge or injection, vitamin B-12 helps develop red blood cells and the sheaths around the nerves. It also has the potential to boost energy levels and the immune system. Side effects of vitamin B-12 are rare.
Anything that goes into the mouth -- food, pill or a lozenge -- triggers the stomach to produce a acid called hydrochloric acid, or HCI. This is a natural, digestive enzyme needed to break down food once in the stomach. When a lozenge is taken, the saliva in the mouth activates HCI. However, because there is an absence of food, the HCI builds up in the stomach, which can lead to nausea. It is a good idea to have food in the stomach when taking a B-12 lozenge.
The daily recommended dose of vitamin B-12 for both men and women is 2.4 micrograms. Over time, if a person exceeds the daily requirement and too much is stored, skin problems may occur in the form of rashes or exacerbated acne. People who have chronic skin problems, such as rosacea or dermatitis, may experience a flare-up. Once you stop or decrease the dose of vitamin B-12, these problems usually resolve. There are no reports of toxic effects to higher-than-recommended doses of vitamin B-12.
Vitamin B-12 Deficiency
Antacid medications, such as proton pump inhibitors and histamine H2 receptor antagonists, may interfere with the absorption of vitamin B-12 lozenges. Metformin, a medication used to treat diabetes also results in poor vitamin B-12 absorption in the stomach. As a result of these medications, a B-12 deficiency may result over time as the body uses up the stored vitamin and not enough is absorbed with supplements.