Further Clinical Investigations Into the Diseases Arising in Consequence of a Deficiency in the Fat-Soluble a Factor

Abstract

My description of the diseases occurring in children from a deficiency in the fat-soluble A factor was quickly acknowledged by those physiologists who were working at vitamin problems. This was due to the close parallel, which in many respects exists between the disease I have observed in children and the condition that can be produced in young rats, by keeping them for a long time on a diet poor in the f at \ x=req-\ soluble A factor but otherwise adequate. With clinicians it was a different matter. Although nearly a decade has passed since I published my first contributions on this subject, there are still many clinicians, especially in Germany, who have never appreciated the fact that the absence of the fat-soluble A factor gives rise to a well defined disease just as, for example, the absence of the C factor does. There are, however, many German authors who trace a connection between the deficient growth of the children and the great prevalence and serious course of tuberculosis and similar diseases during the war on the one hand, and the lack of the proper food substances (i. e., those containing the fat-soluble A factor) on the other, but that it is an indication of the absence of the fat-soluble A factor is usually not understood or not alluded to. With regard to the characteristic symptom, xerophthalmia, it is stated by many that this condition is not caused by a deficiency in the fat-soluble A factor alone but is merely the result of general marasmus.

Consequences of Vitamin A Deficiency: Immunoglobulin Dysregulation, Squamous Cell Metaplasia, Infectious Disease, and Death

“…Children with severe VAD can suffer a chronic dry cough, increased susceptibility to respiratory infections, and pyuria, perhaps due to keratinizing metaplasia at mucosal surfaces [ 32 , 34 , 35 , 36 , 37 ]. Pathologies including UTIs and pyelonephritis have been previously described in Wistar rats and also in humans with VAD [ 32 , 38 , 39 ]. Acute pyelonephritis is a frequent cause of serious bacterial UTIs in infants, with renal scarring followed by hypertension and chronic renal failure being the most common long-term sequelae [ 40 , 41 , 42 , 43 , 44 ].…”

New insights and changing paradigms in the regulation of vitamin A metabolism in development

“…A sufficient intake of vitamin A is critical for normal embryonic development; [42][43][44][45] however, administration of excess vitamin A or ATRA during early pregnancy can lead to congenital malformations of the head, heart, and limbs. [46][47][48][49][50] Hypervitaminosis A has also been associated with abnormal conditions in adults such as an increased risk of bone fractures in the elderly, [51][52][53] and in addition to teratogenic effects, pharmacological doses of ATRA can also cause toxicity associated with symptoms of retinoic acid syndrome.…”

Could the effective mechanisms of retinoids on nephrogenesis be also operative on the amelioration of injury in acquired renal lesions?

“…The relationship between vitamin A and urinary system pathology was first noticed in the first quarter of the twentieth century, when it was proposed that vitamin A played a role in the alteration of the urinary system epithelium and the development of urolithiasis [2]. It has been reported that deficiency of vitamin A increases the susceptibility to urinary tract infections (UTI), and supplementation of vitamin A decreases the incidence of UTI [2,3,4].…”