During the 1920’s and 30’s, Dr May Mellanby undertook “one of the most persistent and intensive investigations that Great Britain has ever seen.” Those investigations included laboratory and clinical studies of the relationship between diet and teeth, and was published in the leading medical journals of the day. The complete study is contained in 3 volumes of Diet and the Teeth: An Experimental Study. A summary of the research by Sir Edward Mellanby can be downloaded here.
Lady Mellanby’s interest in dental research was sparked by her husband, Sir Edward Mellanby, who played a key role in the discovery of vitamin D. Sir Edward was investigating the effect of diet on the development of the disease rickets, which was the scourge of that time. Lady Mellanby noticed that as well as rickets (a bone disease that develops in children usually due to a deficiency of vitamin D), poor diet also affected the structure of developing teeth.
Over the subsequent 20 years she was able to demonstrate that the health and structure of teeth and their susceptibility to decay was determined by the state of the nutrition at the time of tooth formation, beginning before birth. In animal experiments on dogs it was shown that a maternal diet during pregnancy poor in vitamin D with inadequate calcium and phosphorus would cause significant dental defects in the offspring including:
(1) Thick and poorly calcified jaw bone,
(2) Irregularity in the arrangement of the teeth,
(3) Delay in the eruption of the permanent teeth,
(4) Interference with the calcification of the enamel, which is often defectively formed, and
(5) Interference with the calcification of the dentin, which is often poorly calcified.
Unfortunately, these defects are not just limited to animals, but can also be observed in children. The defectively formed teeth are highly prone to subsequent development of tooth decay. However, Lady Mellanby and contemporaries demonstrated conclusively that, despite poorly developed enamel and calcified dentin, with high levels of vitamin D, together with adequate calcium and phosphorus, and particularly in the absence of cereal grains, not only could tooth decay be prevented, but active cavities could consistently be arrested, reversed and that teeth can actually respond and heal without dental intervention.
The discovery by Mrs. Mellanby of the control of tooth formation by the calcifying vitamin, now known as vitamin D, was first published in 1918, and it is now possible to make some estimate of its influence on dental science in general. It is no exaggeration to say that it has indeed been revolutionary. Medical Research Council of Great Britain, 1934.
Lady Mellanby died in 1978.