[Plasma vitamin A in mothers of children with orofacial clefts]

OBJECTIVES

The contribution and exact role of exogenous factors, such as medications and drugs during pregnancy, maternal nutrition, in the etiology of orofacial clefts is not established. Vitamin A is essential for embryogenesis, both the lack and excess of retinol result in congenital malformations.

DESIGN

This study was aimed to establish vitamin A status in Polish mothers of children with isolated orofacial clefts.

MATERIAL AND METHODS

34 mothers of children with isolated cleft lip (CL), 83 mothers of children with cleft lip and palate (CLP), 42 mothers of children with isolated cleft palate (CP) were studied. The control group consisted of 67 women who gave birth to healthy children. All participants were healthy women without symptoms of malabsorption. Plasma retinol levels were determined by high-performance liquid chromatography.

RESULTS

There were no differences in mean plasma vitamin A levels between CL--2.09 +/- 0.61 mumol/l, CLP--2.21 +/- 0.52 mumol/l, CP--2.15 +/- 0.62 mumol/l and control--2.08 +/- 0.52 mumol/l. None of participants had vitamin A deficiency (concentration of retinol < 0.8 mumol/l). Among women, who were not supplemented with retinol containing vitamins during 3 months prior the study, 10.6% of mothers of children with orofacial clefts (n = 132) and only 5.8% of controls (n = 52) had levels of retinol above upper norm for women of childbearing age (N < 2.8 mumol/l).

CONCLUSION

Periconceptional multivitamin supplementation has been reported to decrease the risk of orofacial clefts in offspring, but high intake of preformed vitamin A (retinol) might be undesirable.

Effects of vitamin A pretreatment on nickel-induced lipid peroxidation and concentration of essential metals in liver, kidney and lung of mice

In the present study we report the effects of pretreatment with large doses of vitamin A (Vit A, retinol) on hepatic, renal and pulmonary lipid peroxidation, and Ni and essential metal (Fe, Cu, Zn and Ca) concentrations in mice acutely exposed to nickel. Vitamin A (250,000 IU/kg per day) was administered by oral gavage to ICR mice for 7 days. On the 8th day, NiCl2 (5 mg Ni/kg body wt.) was injected i.p. to Vit A- or vehicle-pretreated mice. Vitamin A pretreatment alone did not alter lipid peroxidation in liver, kidney and lung. Lipid peroxidation in liver, kidney and lung was increased after treatment with NiCl2 alone. The extent of lipid peroxidation levels in Vit A + Ni treated mice was enhanced in liver, but reduced in kidney and lung. The Ni concentration in these three organs was below the detection limit (0.09 microg/g) in control and Vit A-pretreated mice. The accumulation of Ni in Vit A + Ni treated mice was increased in liver, but decreased in kidney and lung compared to Ni-treated mice. The concentrations of Fe, Cu, Zn and Ca in these organs were significantly increased in Ni-treated mice. In Vit A + Ni treated mice, compared to Ni-treated mice, hepatic Fe was significantly increased while Cu, Zn and Ca levels were reduced, but still higher than those of control and Vit A-treated mice. In the kidney of Vit A + Ni treated mice, the increase of Cu, Fe, and Zn but not Ca, was reduced and not significantly different from control and Vit A-treated mice. Pretreatment with Vit A reduced the increased Fe, Cu, Zn and Ca concentration in the lung caused by Ni injection. We therefore conclude that the effect of Vit A pretreatment on Ni toxicity is organ-dependent.

ALTERATIONS IN THE LIPIDS OF BONE CAUSED BY HYPERVITAMINOSIS A AND D

1. The total lipid, phospholipid, total and free fatty acid, free and esterified cholesterol contents of the long bones of normal, hypervitaminotic A, D and A plus D rats were determined. 2. Toxic amounts of vitamin A decreased the total fatty content, whereas toxic amounts of vitamin D increased triglycerides, esterified cholesterol and in particular the phospholipids of bone. 3. An interaction occurred between toxic amounts of vitamins A and D, which prevented, to a large extent, the alterations in bone lipids that occur in hypervitaminosis D. 4. The studies suggest an involvement of vitamin D in lipid metabolism and tend to support the idea that lipids are involved in ossification.

Lipid-laden perisinusoidal cells in patients with acquired immunodeficiency syndrome

Liver biopsies were taken from ten AIDS patients. Liver architecture was normal in all patients. On 1-micron-thick sections stained with toluidine blue, all ten cases showed lipid overload of perisinusoidal cells (1 massive, 5 moderate and 4 mild) compared to 2/8 in control patients, who had mild lipid overload. Other sinusoidal abnormalities such as hypertrophy of Kupffer cells and inclusions in endothelial cells were also noticed. Some hepatocytes presented evidence of cellular damage. Perisinusoidal cell lipid overload was not associated with hypervitaminosis A. We hypothesize that the abnormal accumulation of lipids in perisinusoidal cells (non-induced by hypervitaminosis A) in patients with AIDS could be due to defective transport of vitamin A from perisinusoidal cells to hepatocytes, and/or from hepatocytes to blood. The cause of the defect is unknown. Since lipid overload occurs in many and diverse conditions (diabetes, cholestasis, primary biliary cirrhosis, etc.), it seems reasonable to propose that the defect is non-specific and limited to functional or structural damage of the liver whether induced by drugs, liver or systemic diseases.

Experimental exencephaly and myeloschisis in rats

To elucidate the early sequential morphogenetic progress of exencephaly and myeloschisis, rat embryos whose mothers had been treated with hypervitaminosis A were studied at 1-day interval from gestation day 10.5 to 15.5. In exposed animals sequential change was found in both exencephaly and myeloschisis as the embryos grew up. The 10.5-day old exencephalic embryos had still widely open cephalic neural tubes. Exencephalic embryos older than 13.5 days of gestation showed strikingly severe eversion and overgrowth of the cephalic neuroepithelium, thus failed in forming normal primitive brain. The convex dorsal surface of the exencephaly was covered with ependyma, which was connected directly with surrounding surface eqithelium at the periphery. The earliest morphologically recognized myeloschisis was in the 13.5-day old embryos. In myeloschisis, divergence at the roof plate and eversion of the spinal neural tube, disorganized overgrowth of the neuroepithelium, malformed and misplaced spinal ganglia and nerve roots, and absence of the neural arch and dermal covering were characteristic. It is suggested that exencephaly results from failure of the cephalic neural tube closure which is followed by eversion and overgrowth of the neuroepithelium. And failure in closure of the posterior neuropore and disturbance in the development of the tail bud probably play major role in the morphogenesis of myeloschisis.

Hypervitaminosis A and calcium-regulating hormones in the rat

The effect of vitamin A on calcium-regulating hormones was studied in rats. A single oral dose of 30 mg retinol equivalents (RE) given to adult rats caused no change to serum biologically active parathyroid hormone (bioactive-PTH) concentrations. Bioactive-PTH secretion from rat thyroparathyroid gland complexes was not significantly altered after in vitro incubation with 1.18 X 10(-6) M retinol. Chronically intoxicated rats given 15 mg RE 3 times a week for 6 wk, showed higher osteoclast numbers and lower osteoid than controls. Serum bioactive-PTH was not detectable and serum 25-hydroxyvitamin D (25-OHD) (25.2 +/- 12.5 nmol/L) was significantly (P less than 0.03) lower than controls (43.3 +/- 3.1). In acutely intoxicated rats (60 mg RE/d for 2 d), serum bioactive-PTH levels were significantly lower (0.02 +/- 0.05 ng/ml, P less than 0.03) than in control animals (0.14 +/- 0.08). Lower doses of vitamin A, 7.5 mg RE 3 times a week for 3 wk, suppressed serum bioactive-PTH to undetectable levels but had no significant effect on serum 25-OHD. Serum calcium and 25-OHD levels were significantly lower in vitamin D-intoxicated rats given 7.5 mg RE 3 times a week (ca. 3.16 +/- 0.19 mmol/L; 25-OHD 599.7 +/- 110.6 nmol/L) than vitamin D-intoxicated controls (3.42 +/- 0.17; 789.3 +/- 17.7). These results suggest that hypervitaminosis A can alter the metabolism of calcium-regulating hormones.

Hepatic and dermatologic manifestations of chronic hypervitaminosis A in adults. Report of two cases

Chronic hypervitaminosis A in adults is a clinical syndrome that can develop over varying periods of time depending on the average daily intake of vitamin A. Two adult cases of chronic hypervitaminosis A are described and illustrate this diverse dosage-duration relationship. Hepatic cirrhosis developed as a manifestation of vitamin A toxicity in one of the patients; this appears to be the first reported case of chronic hypervitaminosis A in an adult induced by the long-term frequent ingestion of beef liver.

Determination of retinyl esters and retinol in serum or plasma by normal-phase liquid chromatography: method and applications

Retinol and retinyl esters are measured in serum or plasma samples by gradient, normal-phase, adsorption "high-performance" liquid chromatography, with ultraviolet detection at 325 nm. The four major circulating retinyl esters in humans (esters of palmitate, stearate, oleate, and linoleate) are coeluted as a single peak. Retinyl acetate is included as an internal standard, to correct for variable recovery. Retinol values so measured correlated well (r = 0.88) with those by a widely used reversed-phase chromatographic technique (Clin Chem 1983;29:708-12). The mean retinol concentration was 570 (SEM 17) micrograms/L and the mean for retinyl esters was 33 (SEM 4) micrograms/L as determined in samples from 88 fasting young adults. Concentrations of retinol in plasma as low as 50 micrograms/L can be detected in 100-microL samples, as can 10 micrograms of retinyl esters per liter. Using this method, we measured absorption of low doses of vitamin A, which may provide a more physiological approach to assessment of fat malabsorption. Additionally, the procedure proved useful for quickly screening for vitamin A toxicity. Major advantages include small sample size, direct injection of the extract ed sample without evaporation, rapid elution pattern, co-elution of major retinyl esters as a single peak, and low limit of detection.

Placental transport of retinol in ewes fed high intakes of vitamin A

Twelve ewes were fed retinyl propionate equivalent to 12,000 micrograms retinol/kg body weight per day for the last two trimesters of pregnancy (group fed high vitamin A). Four ewes received a control level of 120 micrograms/kg body weight per day. Indwelling catheters were implanted surgically in fetal jugular veins and carotid arteries. Ewes or fetal lambs received [3H]retinol intravenously, and blood was sampled until parturition. The ewes fed large amounts of vitamin A maintained viable fetal lambs for 6 d less than did controls. Plasma retinyl ester concentrations were elevated in the ewes fed a high level of vitamin A but not in their fetal lambs. Rates of plasma retinol transport and clearance increased with vitamin A intake in ewes and their fetal lambs. Efficiency of placental retinol transport in the group fed high levels of vitamin A was less than one-quarter that for controls. However, placental transport rate was approximately 100 micrograms/d greater than that of controls with an equivalent amount retained by the fetoplacental unit in the group fed high vitamin A. These data indicate that placental transport of retinol is partially regulated. High maternal vitamin A intake results in high retinol transport to the fetus.

Plasma lipoprotein abnormalities associated with acquired hepatic triglyceride lipase deficiency

Two enzymes, lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL), are released into human plasma after intravenous injection of heparin. LPL is the major enzyme responsible for initiating catabolism of chylomicrons and very-low-density lipoproteins (VLDL). The physiological role of HTGL is less certain. HTGL has been postulated to be an alternate enzyme to LPL in hydrolysis of triglyceride in VLDL and to be an important enzyme for removal of phospholipid from both low-density lipoproteins (LDL) and high-density lipoproteins (HDL). In this latter role, this enzyme would convert larger, lighter lipoprotein particles to smaller denser particles. HTGL deficiency has been found in severe liver disease and with a genetic deficiency of this enzyme. A unique patient is described with acquired hepatic triglyceride lipase deficiency and vitamin A intoxication. This patient developed hypercholesterolemia with an increase in both LDL and HDL. An increased proportion of lighter LDL (LDL1) and HDL (HDL2) was noted. In addition, after administration of heparin there was no shift in the distribution of apoE in plasma fractionated using a column containing 4% agarose. These findings are consistent with a postulated role of HTGL in metabolism of light LDL and HDL particles and some classes of apoE containing lipoproteins.

Massive vitamin A intoxication with ascites and pleural effusion

Vitamin A intoxication was diagnosed in a 14-year-old girl who presented with massive exudative ascites and right pleural effusion, impaired liver enzymes, and hypertriglyceridemia. Electron microscopy of liver biopsy material demonstrated numerous perisinusoidal lipid-filled Ito cells. The patient had taken 100-200,000 I.U. vitamin A per day for 15 months. Serum vitamin A level remained elevated for 4 months after vitamin discontinuation. The unusual severity of portal hypertension was documented by a high wedged hepatic vein pressure level. The ascites occurred 2 months after vitamin A had been discontinued, probably owing to particularly slow mobilization of large hepatic stores of vitamin A. Portal hypertension disappeared after a 6-month low vitamin A diet, but the liver biopsy failed to demonstrate any decrease in number or size of Ito cells, suggesting that lipid venous obstruction is unlikely to be the only mechanism responsible for portal hypertension in vitamin A-induced liver disease.

Scintigraphic dissociation of reticuloendothelial and hepatocyte function in chronic vitamin A hepatotoxicity

A discordant hepatic uptake between Tc-99m sulfur colloid and Ga-67 citrate has occurred in an adult patient with hepatotoxicity due to hypervitaminosis A. The authors believe this is a scintigraphic phenomenon related to the characteristics of the radiopharmaceuticals used and does not necessarily represent a true dissociation of various cellular functions of the liver.

[Chronic fatal vitamin A poisoning with hemolytic anemia]

A case of chronic, lethal vitamin A intoxication is reported, the diagnosis of which was not established intra vitam. The patient presented with chronic mixed prehepatic and hepatic icterus and hypersplenism with hemolytic anemia. On post mortem histological examination, abundant deposits of neutral lipids in the reticuloendothelial cells of liver, spleen and bone marrow were found. Chemical analysis of the lipids extracted from these organs revealed esterified fatty acids. Triglycerides could be ruled out since the triglyceride content of the patient's liver was significantly lower than that of a normal control. By means of thinlayer chromatographic analysis it was possible to identify retinol, i.e. retinylester (vitamin A) in the deposits. Vitamin A was determined photometrically and found to be very elevated in the liver and, to a lesser degree, in the spleen of the patient. These findings lead to a definite diagnosis of chronic hypervitaminosis A. Unique features of the case presented are both hemolytic anemia and the lethal outcome of the chronic hypervitaminosis A.

Pibloktoq (hysteria) and Inuit nutrition: possible implication of hypervitaminosis A

The hysterical reaction among Eskimo peoples known as pibloktoq, one of a group of aberrant behaviors occurring among Arctic and Circumarctic societies termed 'arctic hysterias', has been explained by a variety of theories: ecological, nutritional, biological-physiological, psychological-psychoanalytic, social structural and cultural. This study hypothesizes the possible implication of vitamin intoxication, namely, hypervitaminosis A, in the etiology of some cases of pibloktoq. Its biocultural approach implicates elements of several explanatory classes, which are not mutually exclusive. Experimental and clinical studies of nonhumans and humans reveal somatic and behavioral effects of hypervitaminosis A which closely parallel many of the symptoms reported for Western patients diagnosed as hysterical and Inuit sufferers of pibloktoq. Eskimo nutrition provides abundant sources of vitamin A and lays the probable basis in some individuals for hypervitaminosis A through ingestion of livers, kidneys, and fat of arctic fish and mammals, where the vitamin often is stored in poisonous quantities. Possible connections between pibloktoq and hypervitamonosis A are explored. A multifactorial framework may yield a more compelling model of some cases of pibloktoq than those that are mainly unicausal, since, among other things, the disturbance has been reported for males and females, adults and children, and dogs.

[Hydrocephalus during central parenteral feeding. Role of vitamin A poisoning]

Five children receiving central parenteral nutrition presented between the 6th and 16th day of renutrition with hydrocephalus unrelated to intercurrent neurologic disorder. Repeated determinations of plasma retinol and of the transport complex components made the proof of vitamin A intoxication in 2 cases. Vitamin A had been provided in the form of a water-soluble vitamin-solution incorporated in the nutrition mixture (doses: 1,500 micrograms and 3,000 micrograms retinol equivalent respectively). These 2 case reports have to be compared with 3 other cases of hydrocephalus occurring during total parenteral nutrition. One child presented with bilateral jugular thrombosis secondary to percutaneous venous approach trials, while the 2 other were probably within the framework of an accelerated weight recovery following nutritional marasmus.

Fatal hypervitaminosis A in a neonate

Although hypervitaminosis A is not uncommon, fatal cases are rare. We describe a neonate who died after having ingested more than 60 times the suggested dose of vitamin A per day, for 11 days. His hospital course was marked by hypercalcemia, hyperphosphatemia, a bleeding disorder, and pulmonary insufficiency. An autopsy showed extensive calcifications of the alveolar septa and bronchioles. Metastatic calcifications were also present in the kidneys, stomach, soft tissue, and skin. The skeleton showed prominent alteration of the endochondral bone formation. There was also evidence of accelerated resorption of bone, which is presumably responsible for the development of hypercalcemia and metastatic calcification.