Vitamin B1, B2, B6, and C status in hospital inpatients.

The status of vitamin B1, B2, B6 and C was investigated in 656 hospital inpatients by means of a dietary interview, biochemical studies, and clinical investigation. The daily intake was lower than the Recommended Dietary Allowance for vitamin B1 in 57%, B2 in 47%, B6 in 53%, and C in 9% of the patients; it was less than half the Recommended Dietary Allowance in 19, 12, 15, and 3%, respectively. A biochemical deficiency was observed in 25% of the patients for vitamin B1, in 11% for B2, in 25% for B6, and in 14% for C. On the basis of the parameters selected for this study, the biochemical vitamin status, the dietary vitamin intake, and the clinical symptoms correlated significantly with each other except in the case of vitamin B6.

Chemoprevention of indirect and direct chemical carcinogenesis by carotenoids as oxygen radical quenchers.

Beta-carotene (BC) and canthaxanthine (CX), two carotenoids with and without pro-vitamin A activity, respectively, were found to help to prevent benzo[a]pyrene (BP)-induced skin carcinogenesis in the dark and BP photocarcinogenesis (UV 300-400 nm) when given as an oral supplement to female Swiss albino mice. The same experimental procedure was adapted to 8-methoxypsoralen (8-MOP) photoinduction of mammary carcinomas in mice. Here also, the two carotenoids were strongly antitumorigenic. Indeed, 8-MOP photomutagenesis, tested in S. typhimurium TA 102, appeared to depend on a two-step reaction, namely an oxygen-independent DNA-8-MOP photoadduct, followed by an oxygen-dependent second step, sensitive to carotenoids. This result suggests that dietary carotenoids (powerful antioxidant molecules) might prevent the carcinogenic risk caused by substances that are transformed into ultimate carcinogens by oxidative processes which are indirectly carcinogenic. Finally, to verify whether supplemental carotenoids can affect carcinogenesis where neither light excitation nor oxidative metabolic processes are involved, an experimental attempt was made on gastric carcinogenesis induced in rats by the direct carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The results demonstrate that supplemental carotenoids do not affect initiation and progression stages, but do prevent the progression stage of dysplasias to infiltrating gastric carcinomas. Thus, this provides strong presumptive evidence for oxygen radical involvement in the later stages of this neoplastic development, as recently reported in the literature. As far as mutagenicity in S. typhimurium is concerned, carotenoids do not exert, as expected, any protective effect on MNNG mutagenic activity. The above experimental data suggest that supplemental carotenoids, instead of sunscreen preparations, can be adopted by outdoor workers to prevent skin cancer. Accordingly, such natural antioxidants may be useful in human chemoprevention against neoplasias of the lung, breast, urinary bladder, and colon and rectum even after radical surgery.

[B-complex vitamins an the prophylaxis of metabolic diseases (author's transl)]. / Vitamines du groupe B et prophylaxie des maladies métaboliques.

The role of the vitamins of the B group in the therapy of metabolic diseases has been the theme of a recent symposium. All these vitamins exert essential functions in the balance of the intermediary metabolism and consequently in the treatment of their disorders. As far as metabolic diseases and the use of vitamins, i.e. of biological substances, are concerned, the boundaries between the fields of therapy and prophylaxis are difficult to settle strictly. The recent literature concerning these points is reviewed and some concepts discussed.

Therapy of side effects of oral contraceptive agents with vitamin B6.

Studies carried out in different countries during the last 15 years have provided evidence that supplementation with (or excess of) estro-progestational hormones may be accompanied by an increased urinary excretion of tryptophan metabolites, as happens in pyridoxine deficiency. Further methods of assessment of vitamin B6 in humans have confirmed an impaired status in women using hormonal contraception. Disturbances in the metabolism of tryptophan have been shown to be responsible for such symptoms as depression, anxiety, decrease of libido and impairment of glucose tolerance occurring in some of the OCA users. Administration of 40 mg of vitamin B6 daily not only restores normal biochemical values but also relieves the clinical symptoms in those vitamin B6 deficient women taking OCA's. Further studies are justified to clarify whether vitamin B6 supplementation may contribute to improving depression also in other situations with hyperoestrogenism (pregnancy, puerperium, estro-progestational treatments, etc.), as well as correcting metabolic impairments, such as a minor alteration of glucose tolerance.

PIP: Studies carried out in different countries over the last 15 years have provided evidence that supplementation with or excess of estrogen-progestogen hormones may be accompanied by an increased urinary excretion of tryptophan metabolites, as occurs in pyroxidine deficiency. Further methods of assessment of vitamin B6 in humans have confirmed that there is impaired status in women using oral contraceptives (OCs). Disturbances in the tryptophan metabolism have been shown to be responsible for such symptoms as depression, anxiety, decrease in libido, and impairment of glucose tolerance occurring in some OC users. Administration of 40 mg vitamin B6 daily not only restores the normal biochemical values but also relieves the clinical symptoms in those vitamin B6 deficient women taking OCs. Further studies are justified to clarify whether vitamin B6 supplementation may contribute to improving depression in other situations where there is hyperestrogenism (pregnancy, puerperium, estrogen-progestogen treatments), as well as correcting metabolic impairments, such as a minor alteration in glucose tolerance. (author's modified)

Analgesic and antiinflammatory properties of vitamins.

A number of various mechanisms are prone to develop pain symptomatology. Among them infection, inflammation, degeneration, metabolic deviations, and traumas may be at the origin of complex reactions currently gathered under the terminology "rheumatism." For some time now, practitioners have introduced vitamins in the array of their antalgic supply; these were mainly vitamins of the B-group. Meanwhile research has enlarged knowledge about the oxidative mechanisms that are at the origin of inflammation, and has suggested the use of antioxidant substances, among them 9 vitamins. Finally, most of the antalgic drugs used for relief of pains have prooxidative effects, which in turn should be controlled by antioxidant substances. These different interrelations are discussed within the limits of the field of vitamins.

Canthaxanthin retinopathy. An investigation by light and electron microscopy and physicochemical analysis.

The eyes of a patient with canthaxanthin retinopathy were obtained at autopsy and examined by light and electron microscopy. Various tissues of one eye were also studied by physicochemical methods. Morphologically, there were red, birefringent, lipid-soluble crystals in the inner layers of the entire retina. They were particularly large and numerous perifoveally, where they were also clinically visible, but they also occurred frequently in a ring-shaped form peripherally and, less frequently, equatorially. The crystals were located in a spongy degeneration of the inner neuropil, where atrophy of the inner parts of the Müller cells was noticed. The compound isolated from the retina was identical with synthetic canthaxanthin according to mass and proton-resonance spectroscopy. Quantitatively, the retina contained up to 42 micrograms canthaxanthin per gram of tissue besides a minor amount of other carotenoids. Of the other tissues of the eye, only the ciliary body contained measurable concentrations of canthaxanthin. From the great number and size of the crystals, on the one hand, and the relatively small amount of isolated canthaxanthin on the other, it was concluded that the crystals presumably represent a canthaxanthin-lipoprotein complex rather than pure canthaxanthin alone. Examination showed that clinically, only the central portion of the canthaxanthin thesaurismosis, where crystals are packed most densely, can be seen.

Dietary carotenoids block photocarcinogenic enhancement by benzo (a)pyrene and inhibit its carcinogenesis in the dark.

The carotenoids beta-carotene (C) and canthaxanthine (CX), with and without pro-vitamin A activity, respectively, when perorally administered to mice, markedly prevent benzo(a)pyrene photocarcinogenic enhancement (BP-PCE), continue to block such BP-PCE and protect significantly against BP carcinogenesis in mice maintained in the dark. These results appear relevant to both the pathogenesis of chemical carcinogenesis and rational programs of skin cancer prevention in humans.