Vitamin A supplementation and increased prevalence of childhood diarrhoea and acute respiratory infections.

There is uncertainty over whether vitamin A supplementation reduces morbidity among children with subclinical deficiency of the vitamin. Hence a double-blind, placebo-controlled trial of the effect of vitamin A supplementation on childhood morbidity was conducted among 11,124 children aged 6-83 months in the northwest of Haiti. After a random start, children were sequentially assigned by household units to receive either megadose vitamin A or placebo in three distribution cycles 4 months apart. 2 to 8 weeks after each administration of the vitamin A and placebo capsules, indicators of childhood morbidity were reassessed through interviews conducted in the homes of participating families. The vitamin A group was found to have an increased 2-week prevalence of all symptoms and signs of childhood morbidity assessed, including diarrhoea (rate ratio [RR] = 1.09, 95% confidence interval 1.05-1.14), rhinitis (RR = 1.02, 95% confidence interval 1.00-1.04), cold/flu symptoms (RR = 1.04, 95% confidence interval 1.01-1.06), cough (RR = 1.07, 95% confidence interval 1.03-1.11), and rapid breathing (RR = 1.18, 95% confidence interval 1.09-1.27). The study shows an increased 2-week prevalence of diarrhoea and the symptoms of respiratory infections after vitamin A supplementation.

PIP: In the late 1980s, 11,124 children 6-83 months old, living in the sparsely populated northwest of Haiti participated in a double-blind, placebo-controlled trial of the effect of vitamin A supplementation on child morbidity. An ophthalmic assistant and a supervising ophthalmologist examined all children 2 years old. 30 children had vitamin A deficient related corneal disease (20 with corneal xerosis and 10 with corneal ulceration, keratomalacia, and/or corneal scarring). The children received either a capsule containing 200,000 IU of vitamin A and 40.6 mg vitamin E or a capsule containing only 40.6 mg vitamin E (placebo) every 4 months. Field workers interviewed caretakers 2-8 weeks after the children received their capsules to gather data on signs and symptoms of illness. Children in the vitamin A group were more likely to have a higher prevalence of diarrhea and of respiratory infections than the placebo group (e.g., 1st cycle, 42 vs. 36% for diarrhea and 18 vs. 15% for rapid breathing, rate ratios = 1.6 and 1.19, respectively). The risk of morbidity was highest 8-17 weeks after receiving the megadose of vitamin A. These findings indicate that prevalence of diarrhea and respiratory infections increased 2 weeks after vitamin A supplementation. Mortality rates of the 2 groups were essentially the same. The mortality rate of nonparticipants was higher than that of participants (52/1000 vs. 23/1000), however, suggesting that the supplements may have had some benefit.

Tolerance of young infants to a single, large dose of vitamin A: a randomized community trial in Nepal.

A randomized, double-masked trial was carried out in rural Nepal to investigate the incidence and severity of acute side-effects among neonates ( < 1 month of age) and infants aged 1-6 months who received a large, oral dose of vitamin A (15,000 retinol equivalents (RE) (50,000 IU) and 30,000 RE (100,000 IU), respectively) or placebo (75 RE (250 IU) and 150 RE (500 IU), respectively) in oil. Infants (vitamin A group, n = 1461; controls, n = 1379) were assessed for vomiting, loose stools, fever, and irritability during the 24 hours before and after dosing. Fontanelles were palpated 24 hours after dosing. Neonates exhibited no excess risk of adverse side-effects after receiving 15,000 RE. Compared with controls the older infants who ingested 30,000 RE had a 1.6% excess rate of vomiting (95% confidence interval (CI): 0.2-3.0%) and a 0.5% excess rate (95% CI: -0.1 to 1.1%) in the occurrence of bulging fontanelles. There were no other significant differences in the older infants. The controlled, periodic distribution of a single 15,000 RE dose of vitamin A therefore confers no apparent acute risk to young infants; a 30,000 RE dose is associated with a minimum risk of transient, acute side-effects.

[Mega-dosages vitamin D: progressive medicine?]. / Megadoses vitamine D: progressieve geneeskunde?

Although the risk of vitamin intoxication is well recognised, massive doses of these preparations continue to be prescribed, especially in the so-called 'alternative' medical sector. We describe a patient with hypervitaminosis D due to administration of megadoses of vitamin D in the absence of an obvious indication. Mode of action and symptoms of vitamin D intoxication are discussed. It is emphasized that vitamin preparations should only be used when strictly indicated and that close clinical and biochemical supervision is necessary.

Hypervitaminosis A causing benign intracranial hypertension. A case report.

Hypervitaminosis A is a well-recognized clinical entity, but the toxic manifestations develop so insidiously and involve so many systems that diagnosis can easily be missed or delayed. A patient with juvenile chronic arthritis developed benign intracranial hypertension and other manifestations of excessive vitamin A intake and made a complete recovery after it was withdrawn. Vitamin A is a non-prescription drug and any history of its ingestion must be obtained during evaluation of papilloedema. A plea is made for the public to be repeatedly reminded that no proposed remedy is safe or effective until it is demonstrated to be so.

Vitamin supplementation and megadoses.

Almost one-third of American adults regularly take vitamins and supplements. If taken incorrectly or in excess, these vitamins may be a potential health hazard. Vitamins are essential nutrients which, in combination with other nutrients (e.g., fats, carbohydrates and proteins), foster normal metabolism. Vitamins also interact with each other. For example, vitamin C participates in the metabolism of folic acid, and vitamin E facilitates the absorption and storage of vitamin A. Because the biological functions of vitamins are interrelated, a diet poor in vitamins, carbohydrates, fats and proteins is not necessarily enhanced by vitamin supplementation. When vitamins are taken in excess of the Recommended Dietary Allowances or the individual's needs, the vitamins no longer function as vitamins but instead act as drugs, with such pharmacological effects as clinical toxicities and the abnormal utilization of vitamins. There are six categories that require vitamin supplements and, in some cases, megadoses. These will be discussed in detail. In addition, a brief table showing the Recommended Dietary Allowances will be given which the nurse practitioner can use in assessing nutritional needs of the client so that necessary adjustments can be made. Finally, a brief review of the potential risks and benefits of megadoses in normal, healthy adults will be given.

Transient neonatal zinc deficiency.

We report an infant who developed clinical manifestations of zinc deficiency during the first month of life although the diet was adequate for zinc and no other causes could be ascertained. The diagnosis was confirmed by low plasma-zinc concentrations and a positive response to zinc treatment. The fatty acid profile of plasma phospholipids was typical of zinc deficiency (ie, arachidonic acid was markedly decreased). The transient nature of this disorder was evident when no relapse occurred after cessation of zinc therapy and plasma-zinc and arachidonic acid concentrations remained normal. Several explanations for the development of transient neonatal zinc deficiency are offered. The observation demonstrates that occasional infants may have requirements for zinc that are beyond the intakes of the conventional RDA.