This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Piorry furnishes evidence of the value of phosphates in osteo-malacia, or softening of the bones generally, also in spinal caries or "Pott's disease" (Gazette des Hopitaux, 1856), and I have certainly seen them very beneficial in cases of caries and joint disease. Reasoning from the observation that birds with a broken limb lay eggs without shell during the process of repair, Dr. Fletcher was led to administer a mixture of calcined bone, prepared chalk, and lime-water in cases of fracture (in man), and reported several cases of very early union of long bones (Lancet, 1846). Milne Edwards made similar observations on dogs and rabbits, producing fractures as nearly as possible alike, and then finding that the animals who got lime phosphate recovered more rapidly than the others; and M. Gosselin found the same results in men (Comptes Rendus, xiii., p. 631; and British and Foreign Review, July, 1856): on the other hand, it has been pointed out that in fractures of old persons, in whom the bones are brittle, lime salts are better avoided. They have been strongly recommended during pregnancy and lactation in enfeebled mothers, both to relieve their neuralgia, debility, and dyspepsia, and also to favor the development of healthy non-rachitic children (Der Prakt. Arzt, May, 1869); and I have for years recommended their use in backward dentition, delayed power of walking, and retarded closure of the fontanelles. These are usual signs of a rachitic tendency, and in the fully-developed malady of rachitis, saccharated lime is strongly to be recommended. It is true that although parts of the bones become softened in this disease, and are deficient in lime, often at the same time, lime phosphates are largely excreted in the urine, so that the fault is one rather of mal-assimilation than of actual deficiency, yet I agree with Dr. Ringer that the administration of lime, and especially of lime-phosphate, "appears to control this defective and perverse nutrition, and to induce healthy growth, so as to favor consolidation of the skeleton and improve the condition of soft parts," and that practically they are extremely valuable, though not always alone curative. He compares this use of it to that of iron in anaemia, where the fault is equally one of want of assimilation rather than of quantity. As already mentioned under the physiological action of lime (v. p. 99), it has been objected that it is so little soluble that quite sufficient may be introduced with ordinary food, and that to give it in medicine rather interferes than otherwise with normal nutrition (Paquelin and Jolly); but practically we do not find it so. Considering, however, the evident insolubility of ordinary tribasic phosphate, M. Dusart and others have introduced acid solutions - lacto-phosphates - which have come much into vogue, and are sometimes very suitable, but it must be remembered that often in unhealthy rachitic children most of the secretions are already too acid, and need rather to be neutralized by a basic earthy salt, and any excess of acid would tend rather to dissolve osseous salts, and cause them to be eliminated, not deposited. It may often be better to give the ordinary salt (phosphate) recently prepared, if possible, and with flour or milk, and to trust the stomach to absorb what is needed, and the surplus will pass through the intestine, not injuriously. The combination of lime phosphate with sodium chloride (calcaria phosphorica salita) has been found very soluble (Sabellin, Dorogow, Husemann, p. 724). The sulpho-carbolates of lime have been specially recommended in rickets, but Dr. C. Ritchie did not find them serviceable (Medical Times, i., 1871).
There is reason to think that natural salts of lime, such as have recently passed through organic structures, are preferable to such as have been deposited as mineral. Thus, Piorry recommended, in bone-softening and spinal curvature, fine filings of fresh bone, 1 oz., to be taken in milk or rice-milk, and found it succeed when proper light, warmth, and food had failed (Gazette des Hopitaux, 1856, No. 139; Medical Times, i., 1857).
Others have derived medicinal phosphates from the vegetable kingdom. Thus Dr. Hake and Dr. Tilbury Fox recommend a strong decoction of good bran to be made and evaporated, and the residue mixed with sugar; and a preparation of this kind known as "saccharated wheat phosphates" has come largely into use for mal-nutrition, rickets, etc. (Medical Times, i., 1866). It may be desirable to state again that the advantage of lime salts in bone disease is not traced simply to chemical and physical processes, but also to direct improvement of digestion, absorption, and nutrition.