Overlapping vitamin A interventions in the United States, Guatemala, Zambia, and South Africa: case studies.

Vitamin A (VA) deficiency is a serious public health problem, especially in preschool children who are at risk of increased mortality. In order to address this problem, the World Health Organization recommends periodic high-dose supplementation to children 6-59 months of age in areas of highest risk. Originally, supplementation was meant as a short-term solution until more sustainable interventions could be adopted. Currently, many countries are fortifying commercialized common staple and snack foods with retinyl palmitate. However, in some countries, overlapping programs may lead to excessive intakes. Our review uses case studies in the United States, Guatemala, Zambia, and South Africa to illustrate the potential for excessive intakes in some groups. For example, direct liver analysis from 27 U.S. adult cadavers revealed 33% prevalence of hypervitaminosis A (defined as ≥1 µmol/g liver). In 133 Zambian children, 59% were diagnosed with hypervitaminosis A using a retinol isotope dilution, and 16% had ≥5% total serum VA as retinyl esters, a measure of intoxication. In 40 South African children who frequently consumed liver, 72.5% had ≥5% total serum VA as retinyl esters. All four countries have mandatory fortified foods and a high percentage of supplement users or targeted supplementation to preschool children.

Hypercarotenodermia in Zambia: which children turned orange during mango season?

Vitamin A (VA) deficiency is a public health problem in many countries. The World Health Organization recommends high-dose VA supplements to children aged 6-59 months based on unequivocal evidence that supplements decreased mortality risk. VA supplements were meant as a temporary intervention until more sustainable approaches could be implemented. Fortification of processed foods with preformed VA is a means to improve VA status. The most recent addition of retinyl palmitate to cooking oil in countries that may also fortify margarine and milk will undoubtedly have a positive impact on VA status. However, quantitative measures have not been used to assess the underlying VA status of the groups who have adopted widespread fortification. The addition of preformed VA to otherwise adequate diets in VA may cause excessive total body stores. Monitoring population status will require accurate VA assessment to ensure that hypervitaminosis does not prevail. This perspective describes a cohort of rural Zambian children who have adequate diets in VA, mostly as provitamin A carotenoids; who were given high-dose VA supplements till the age of 5 years; who have access to VA-fortified sugar; and whose mothers had access to VA-fortified sugar throughout pregnancy and lactation. Many of these children turned orange during mango season, and this phenomenon occurred at estimated liver reserve concentrations >1 µmol retinol equivalents/g liver. It will be necessary to continue to monitor VA status, including all sectors of the population that have access to successful interventions, to optimize health with the intent to lower retinol content of fortified foods or better target VA supplementation to areas of most need.

Individualized vitamin A supplementation for patients with cystic fibrosis.

BACKGROUND & AIMS: To determine the vitamin A status and appropriate supplementation dosage of cystic fibrosis (CF) patients who received vitamin A supplementation based on annual serum retinol measurements. METHODS: Vitamin A food intake, supplementation dosage, and serum retinol levels were obtained for 32 CF patients >4 years of age (4.3-27.3 years old) who had pancreatic insufficiency and mild-to-moderate lung disease (percent predicted of forced expiratory volume in 1 s > 40%). These measurements were compared with the dietary reference intake for healthy children and adults (D-A-CH dietary recommendations), US and German CF recommendations, and serum retinol concentrations from National Health and Nutrition Examination Survey (NHANES) data. RESULTS: Total vitamin A intake from food and supplementation was 315% ± 182% of D-A-CH recommendations, with 65% from supplements. The range of the prescribed vitamin A supplementation dosage was 0-20,000 IU/day (median 5500 IU), and it was consistent with CF recommendations in 28% of participants. A quarter of all patients did not need any vitamin A supplementation. The total vitamin A intake exceeded the recommended upper limit of intake in 69% of subjects. The mean (range) serum retinol was 38.6 µg/dl (22.1-59.1 µg/dl). All subjects had serum retinol levels above 20 µg/dl and below 72 µg/dl (95th percentile of NHANES reference range). CONCLUSION: Individualized vitamin A supplementation of 0-20,000 IU/day based on annual serum retinol measurements may prevent deficiency and high serum retinol levels, but it may lead to vitamin A intake above the tolerable upper intake level.

Evaluation of vitamin A supplementation in Gulshan-e-Sikandarabad.

INTRODUCTION: Vitamin A deficiency (VAD) causes blindness of 250,000 to 500,000 children annually, around the world. It also increases the risk of morbidity and mortality due to other diseases. Pakistan is categorized in the 'Severe Sub-Clinical Deficiency' group. A mass supplementation program has been started in 1999. AIM: To determine the coverage of vitamin A supplements in children under five years of age, and to assess the incidence of symptoms related to hypervitaminosis A. SETTING: Block I-A of Gulshan-e-Sikanderabad. METHODOLOGY: A survey was conducted, using the fourth year MBBS students of Ziauddin Medical University (ZMU), under faculty supervision. A pre-tested structured questionnaire was used to assess coverage and symptoms of toxicity. RESULTS: Data was obtained on 489 children. The coverage of polio and vitamin A supplementation was 88% and 74.8%, respectively. In all 15 children (4.4%) experienced symptoms of toxicity related to vitamin A supplementation. CONCLUSION: Although vitamin A supplementation can save lives, it is only a short term measure. What is needed is a multi-strategy approach including short and long term strategies.

Safety of vitamin A.

Vitamin A adequacy is discussed in terms of the recommended allowances appropriate for the needs of the majority of individuals. Deficiency can result in xerophthalmia and permanent blindness and in increased mortality rates among children. Toxicity has been associated with the overconsumption of vitamin A supplements. Acute hypervitaminosis A may occur after ingestion of greater than or equal to 500,000 IU (over 100 times the RDA) by adults or proportionately less by children. Symptoms are usually reversible on cessation of overdosing. Factors influencing chronic hypervitaminosis A include dosing regimen, physical form of the vitamin, general health status, dietary factors such as ethanol and protein intake, and interactions with vitamins C, D, E, and K. Both excess and deficiency of vitamin A in pregnant animals was shown to be teratogenic. In humans, congenital malformations associated with maternal over-use of high doses of vitamin A were reported but no cause-and-effect relationship has been established. Deficiency of the vitamin during pregnancy has also been associated with congenital abnormalities. Reported incidences of vitamin A toxicity are rare and have averaged fewer than 10 cases per year from 1976 to 1987.