Absorption of Topically Applied Vitamins

Some factors affecting the level of vitamin D in the blood of sheep

“…Truter (1956) quotes three workers who confirm the presence of such provitamins or vitamins in wool wax. Vitamin D can be absorbed through the skin as readily as through the intestinal wall (Schaefer, Sassaman, Slocum & Greene, 1956). The factors that affect the amount of the U.V.…”

Sunlight, Ozone and Vitamin D

“…The rates of these various processes in the body have not been experimentally quantified although it is known that ointments containing vitamin D are rapidly effective (Schaeffer et al, 1956). If the pre-vitamin to vitamin conversion occurs thermally, as it does in vitro, then it would require about 24h to convert half the pre-vitamin (tx ^ 24 h) and this is obviously slow compared with photochemical reactions.…”

Percutaneous absorption

“…The barrier layer is 10 p thick and prevents the penetration of molecules having molecular weights greater than 200 or 300 (17); yet the diameter of the pores in the material in the intercellular spaces in the barrier is much larger than the largest penetrating molecule. Thus, the restraining force must be the molecular interaction between penetrant and pore contents.…”

“…Absorption has been demonstrated in animals (196, ,198) and in man (198,199). The percutaneous absorption of vitamin Bg (200, 20l), thiamine hydrochloride (200,202), riboflavin (200), calcium pantothenate (200), and vitamin C (203) has also been reported.…”