Dr David Wood BVSc, MRCVS
Vitamins are classified as either oil-soluble (A, D, E & K) or water-soluble (B Group & Vitamin C).
The water-soluble ones can be administered intravenously but the oil soluble group can only be injected into the muscle. Vitamin injections bypass the need for absorption through the intestinal wall and produce high blood levels rapidly but in the case of the B Group especially, are also rapidly excreted via the kidneys or liver. The high blood concentration achieved following injection triggers the body’s mechanisms both to use the vitamin and to get rid of any which is surplus to immediate requirements.
Repeated oral supplementation via daily dosing provides constant intake over time so the body always has the vitamins it needs available, avoiding the roller coaster high and lows which may be associated with injections. Studies on Vitamin B12 for example have shown that oral supplementation is just as effective at achieving a response as repeated injections.
Water soluble vitamins cannot be stored by the body so constant replenishment via oral supplements is probably preferable to intermittent high dose injections. Where a severe deficiency has produced disease then rapid high dose replenishment by injection may be appropriate, but for routine maintenance of adequate levels, the oral route is preferable, as nature intended.
Horsepower’s range of oral Vitamin Supplements are available from your local produce, or can be purchased online here