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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cystic fibrosis as a specific disease entity has been known to be associated with malnutrition for almost half a century. The importance of the malnutrition in the disease process remains unknown, as does much information about specific nutritional deficiencies in CF. Supplements for children with CF should include extra energy as fat or carbohydrate, a form of linoleic acid that can be absorbed, hydrolyzed protein, fat-soluble vitamins with vitamins A and E in a water emulsion, vitamin B12, probably B vitamins and vitamin C, and trace minerals. Routine measurements of nutritional status, particularly in children with growth failure, should be made at regular intervals and should include a three-day diet record and a simultaneous 72-hour stool fat determination. If fat malabsorption is not controlled by pancreatic enzymes, the use of antacids or cimetidine should be considered. The true role of nutrition in patients with CF will not be known until the appropriate studies are completed.
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PMID:Cystic fibrosis and malnutrition. 38 15

Previously reported levels of iron absorption from common Southeast Asian meals composed of rice, vegetables, and spices were too low to be consistent with the known prevalence of iron deficiency. In the present paper the cause of the low absorption was systematically sought. Variables investigated comprised methodological errors, factors in the diet such as certain foodstuffs, or contaminants inhibiting the absorption and characteristics of the subjects accompanied by malabsorption of dietary iron. The latter was excluded by comparing the absorption from both wheat rolls and a composit rice meal in Thai and Swedish women using the absorption of a small dose of ferrous ascorbate as a common basis of comparison. Two main factors were identified as causing the low absorption in the previous studies: the homogenization of the labeled meals before serving and the use of rice flour instead of rice. Iron absorption from nonhomogenized meals of identical composition as studied previously was many times higher (on an average 0.16 mg) and was consistent with the actual prevalence of iron deficiency in lower socioeconomic groups of Thais mainly consuming the simple meals studied. Recent modifications of the method to measure nonheme iron absorption from composite meals have thus not only made the determination simpler but also more accurate.
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PMID:Iron absorption from Southeast Asian diets. II. Role of various factors that might explain low absorption. 85 Oct 82

Plasma or erythrocyte levels of ten nutrients (vitamins A, C, B12 and B6; folate; thiamine; riboflavin; zinc; copper; iron) were assayed in 73 patients with various forms of inherited epidermolysis bullosa (EB). Whereas the mean level for each nutrient was within its normal range, deficient levels were noted in individual EB subsets for selected nutrients. Notable abnormalities included low levels of plasma iron and zinc (in junctional EB and recessive dystrophic EB), vitamin C (primarily in EB simplex), vitamin A (in junctional and recessive dystrophic EB), vitamin B12 (primarily in EB simplex), and vitamin B6 (especially in recessive dystrophic EB). With the exception of low plasma iron and zinc levels in junctional and recessive dystrophic EB, however, only a minority of patients in any of the EB subsets had low levels of most of the other nutrients, and an apparent correlation with malabsorption was possible with only selected nutrients.
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PMID:Blood vitamin and trace metal levels in epidermolysis bullosa. 292 44

An investigation of variables important to calcium stone formation in urine indicated significantly increased daily excretion of calcium and oxalate and decreased excretion of ascorbate and citrate by recurrent calcium stone formers. In addition, urine volume, sodium, mucopolysaccharide, and protein were also significantly increased. We compared the uptake of citrate and ascorbate from the gut into the blood in normal controls and stone formers. These studies indicated significantly depressed absorption of both these hydroxycarboxylic acids in recurrent calcium stone formers. We also found that concurrent administration of citrate inhibited ascorbate absorption and increased urinary oxalate excretion after an ascorbate load in normal subjects and stone formers. These findings suggest a mechanism that explains hyperoxaluria in stone patients on the basis of a malabsorption of citrate, ascorbate, and possibly other hydroxycarboxylic acids.
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PMID:Chemical factors important to calcium nephrolithiasis: evidence for impaired hydroxycarboxylic acid absorption causing hyperoxaluria. 380 7

Vitamins are a group of organic compounds occurring naturally in food and are necessary for good health. Lack of a vitamin may lead to a specific deficiency syndrome, which may be primary (due to inadequate diet) or secondary (due to malabsorption or to increased metabolic need), and it is rational to use high-dose vitamin supplementation in situations where these clinical conditions exist. However, pharmacological doses of vitamins are claimed to be of value in a wide variety of conditions which have no, or only a superficial, resemblance to the classic vitamin deficiency syndromes. The enormous literature on which these claims are based consists mainly of uncontrolled clinical trials or anecdotal reports. Only a few studies have made use of the techniques of randomisation and double-blinding. Evidence from such studies reveals a beneficial therapeutic effect of vitamin E in intermittent claudication and fibrocystic breast disease and of vitamin C in pressure sores, but the use of vitamin A in acne vulgaris, vitamin E in angina pectoris, hyperlipidaemia and enhancement of athletic capacity, of vitamin C in advanced cancer, and niacin in schizophrenia has been rejected. Evidence is conflicting or inconclusive as to the use of vitamin C in the common cold, asthma and enhancement of athletic capacity, of pantothenic acid in osteoarthritis, and folic acid (folacin) in neural tube defects. Most of the vitamins have been reported to cause adverse effects when ingested in excessive doses. It is therefore worthwhile to consider the risk-benefit ratio before embarking upon the use of high-dose vitamin supplementation for disorders were proof of efficacy is lacking.
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PMID:Vitamin therapy in the absence of obvious deficiency. What is the evidence? 623 Feb 19

Nutritional status indicators were assessed chemically in blood and urine taken from 625 Transkeians drawn from three age-groups in each of two regions: one with a moderate risk for esophageal cancer and one with a very high risk. Aggregate mean values for protein, albumin, vitamin A, and phosphorus were generally acceptable, but many subjects had inadequate (though not necessarily deficient) values for nicotinic acid (74% of subjects), magnesium (60%), vitamin C (55%), carotene (53%), riboflavin (41%), calcium (35%), and zinc (27%). Groups at highest risk for esophageal cancer had markedly lower serum magnesium and carotene concentrations and mildly depressed hemoglobin and hematocrit values, but such findings are not necessarily associated with esophageal cancer etiology. Possible intestinal malabsorption in the populations at highest risk may be associated with the unusually high fiber and phytate intake of the high-risk populations as well as with exposure to necrotizing mycotoxins. Thus, while protein and energy nutriture seem generally adequate, both the high- and moderate-risk populations had high incidences of multiple micronutrient malnutrition.
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PMID:Nutritional status of African populations predisposed to esophageal cancer. 684 45

After the development of monophasic combined oral contraceptives (COCs), containing a fixed dose of estrogen and progestogen, biphasic and triphasic COCs were introduced in the 1980s; in these the dose of ethinyl estradiol and progestogen changes during the pill cycle. In the so-called every day pills, the 21 pills of active steroid combination are followed by 7 inactive pills containing starch, iron, or bran. Method failures of OCs are among the lowest ranging from 0.2-1/100 woman-years. User failures can be as high as 6.2/100 women-years. The individual difference in peak plasma levels of estrogens in women taking identical OCs can be 10-fold. Conditions that affect the bioavailability of contraceptive steroids are: 1) drug interaction (vitamin C, drugs that induce liver enzymes, and antibiotics); 2) vomiting; 3) vegetarianism; 4) missing pills; and 5) malabsorption. Metabolic effects of COCs pertain to carbohydrate metabolism, lipid metabolism, hemostasis, and vitamins. Prescribing of COCs involves counseling clients about contraindications to COCs, starting routines, and the pill-free interval, as well as follow-up and monitoring, the problem of missing pills, and selection criteria for OC use. Medical conditions in which COC use requires special consideration are sickle cell disease, trophoblastic disease, HIV disease, gallstones, epilepsy, valvular heart disease, oligomenorrhea/amenorrhea, inflammatory bowel disease, and surgery. Side effects of COCs may include depression, nausea, vomiting, headaches, urinary tract infection, and lower genital tract infections. 6 months after stopping the OC 1% of users become amenorrheic. Many of the common causes of amenorrhea, such as weight loss amenorrhea and polycystic ovarian disease, may be treated with the COC until the couple desires to have a baby. The new progestogens desogestrel, norgestimate, and gestodene are highly selective compared to first and second generation progestogens.
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PMID:Combined oral contraceptives: acceptability and effective use. 832 4

We measured plasma levels of all the antioxidant-micronutrients in subjects with HIV infection and controls. Plasma levels of all the carotenoids, including lutein, cryptoxanthin, lycopene, alpha-carotene and beta-carotene as well as vitamins A, C and E and cholesterol were assayed in 35 subjects with HIV infection and 38 controls. We found a significant depletion of all the carotenoids (P < 0.001) and vitamin C (P < 0.01) and cholesterol (P < 0.001) but not vitamins A or E in HIV-infected subjects. Further analysis of the HIV-infected subjects revealed that plasma levels of 4 of the groups of carotenoids and cholesterol were correlated with CD4 count but that beta-carotene and vitamins A, C and E were not. These results are reviewed in the light of the published literature and we conclude that these abnormalities of antioxidant-micronutrients are likely to reflect a metabolic phenomenon associated with HIV infection. However, an additional contribution to these deficiencies from malabsorption later in HIV disease cannot be ruled out.
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PMID:Antioxidant-micronutrients and HIV infection. 911 64

Reaction of 5a-bromo-alpha-tocopherol with ascorbic acid produces 5a-tocopheryl ascorbate which is designated "vitamin CE." This novel tocopherol derivative represents an interesting prodrug form of alpha-tocopherol (vitamin E) that is stable under acidic conditions, but regenerates finely dispersed vitamin E in basic media. The reaction mechanism of the base-induced decomposition of vitamin CE involves elimination of ascorbate and production of an ortho-quinone methide intermediate that oxidizes ascorbate, and is reduced to vitamin E. Kinetic experiments showed reaction to proceed in the pH range of 8 to 11 under physiological conditions. Tissue culture measurements demonstrated that vitamin E generated from the novel derivative is absorbed at much higher rates than conventional preparations and can even be absorbed under simulated conditions of malabsorption where there is no uptake of conventional vitamin E medications.
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PMID:"Vitamin CE," a novel prodrug form of vitamin E. 921 11

In this review the effects of lifestyle factors, especially alcohol consumption, on vitamin bioavailability are summarized and discussed. Alcohol effects are clearly dose-dependent. Excessive chronic alcohol intake is generally associated with vitamin deficiency (especially folate, thiamine, and vitamin B6) due to malnutrition, malabsorption, and ethanol toxicity. Effects of moderate alcohol use are mainly explained by a lower vitamin intake. In the case of vitamin A and beta-carotene, effects on post-absorptive (lipoprotein) metabolism have been demonstrated. In one diet-controlled crossover study, alcohol consumption resulted in an increase in the plasma vitamin B6 (PLP) content, especially after beer consumption (containing vitamin B6), but also after wine and spirit consumption (not containing vitamin B6). Smoking is also associated with a lower dietary vitamin intake. In the case of vitamin C, B12, folate, and beta-carotene, evidence has been presented for effects on postabsorptive metabolism, due to smoke-induced oxidative stress and/or vitamin inactivation. For vitamin E a direct effect of smoking on absorption has been demonstrated. There is no convincing evidence that low-fat diets negatively affect fat-soluble vitamin absorption, but cholesterol-lowering compounds (diets), or unabsorbable fat substitutes, may do so. Vitamin bioavailability may be compromised from certain vegetables (particularly raw), and/or from high-fiber foods, because of limited digestion and inefficient release of vitamins from the food matrix.
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PMID:Influence of lifestyle on vitamin bioavailability. 1188 54


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