Pregnancy support- Vitamin Deficiencies

Beta Carotene - updated: 03 November 2008

Vitamin A intake and status

Eur J Clin Nutr. 1996 Jul;50 Suppl 3:S7-12

van den Berg H.

OBJECTIVE: To review the methodology for vitamin A intake and status assessment and to discuss available data on vitamin A intake and status in the Netherlands. CONCLUSIONS: For diagnosis of a deficient vitamin A status, a number of valid biochemical and functional tests and criteria for interpretation are available. However, the sensitivity and specificity of most tests for assessment of the vitamin A status in the suboptimal and/or marginal range seem troublesome. The average vitamin A intake in the Netherlands (adult men 830 RE; adult women 650 RE) is slightly below the Dutch RDA (men 1000 RE; women 800 RE. In particular, individuals avoiding liver and liver products have lower intakes and might have limited stores. The functional significance of these findings remains to be established.

Publication Types:

• Review

The WHO programme of prevention and control of vitamin A deficiency, xerophthalmia and nutritional blindness

Nutr Health. 1986;4(2):105-12

DeMaeyer EM.

The vast extent and the world wide distribution of vitamin A deficiency is discussed. Its epidemiology is reviewed and sources of vitamin A in diets recorded, along with the high requirements of children. Strategy for prevention is described under three headings--short, medium and long term steps. Strategies in many countries received notice. PIP: Conservative estimates project over 500,000 cases/year of new active corneal lesions and 6-7 million cases of noncorneal xerophthalmia attributable to vitamin A deficiency on a worldwide basis. Vitamin A deficiency affects growth, the differentiation of epithelial tissues, and immune competence. The most dramatic impact, however, is on the eye and includes night blindness, xerosis of the conjunctiva and cornea, and ultimately corneal ulceration and necrosis of the cornea. Vitamin A deficiency occurs when body stores are exhausted and supply fails to meet the body's requirements, either because there is a dietary insufficiency, requirements are increased, or intestinal absorption, transport and metabolism are impaired as a result of conditions such as diarrhea. Vitamin A deficiency is the single most frequent cause of blindness among preschool children in developing countries. The younger the child, the more severe is the disease and the higher the risk that corneal destruction will be followed by death. The most important step in preventing vitamin A deficiency is ensuring that children's diets include adequate amounts of carotene containing cereals, tubers, vegetables, and fruits. An overall strategy designed to prevent and control vitamin A deficiency, xerophthalmia, and nutritional blindness may be defined in terms of action taken in the short, medium, and long term. A short-term, emergency measure includes the administration to vulnerable groups of single, large doses of vitamin A on a periodic basis. In the medium-term, the fortification of a dietary vehicle (e.g., sugar or monosodium glutamate) with vitamin A can be initiated. Increased dietary intake of vitamin A through home gardening and nutrition education programs comprises the longterm solution to this problem. The World Health Organization plans to launch a 10-year program of support to countries where vitamin A deficiency is a significant public health problem.

Publication Types:

• WHO Study

The importance of beta-carotene as a source of vitamin A with special regard to pregnant and breastfeeding women.

Eur J Nutr. 2007 Jul;46 Suppl 1:I1-20

Strobel M, Tinz J, Biesalski HK.

Vitamin A is essential for growth and differentiation of a number of cells and tissues. Notably during pregnancy and throughout the breastfeeding period, vitamin A has an important role in the healthy development of the fetus and the newborn, with lung development and maturation being particularly important. The German Nutrition Society (DGE) recommends a 40% increase in vitamin A intake for pregnant women and a 90% increase for breastfeeding women. However, pregnant women or those considering becoming pregnant are generally advised to avoid the intake of vitamin A rich liver and liver foods, based upon unsupported scientific findings. As a result, the provitamin A carotenoid beta-carotene remains their essential source of vitamin A. Basic sources of provitamin A are orange and dark green vegetables, followed by fortified beverages which represent between 20% and 40% of the daily supply. The average intake of beta-carotene in Germany is about 1.5-2 mg a day. Assuming a vitamin A conversion rate for beta-carotene for juices of 4:1, and fruit and vegetables between 12:1 and 26:1; the total vitamin A contribution from beta-carotene intake represents 10-15% of the RDA. The American Pediatrics Association cites vitamin A as one of the most critical vitamins during pregnancy and the breastfeeding period, especially in terms of lung function and maturation. If the vitamin A supply of the mother is inadequate, her supply to the fetus will also be inadequate, as will later be her milk. These inadequacies cannot be compensated by postnatal supplementation. A clinical study in pregnant women with short birth intervals or multiple births showed that almost 1/3 of the women had plasma retinol levels below 1.4 micromol/l corresponding to a borderline deficiency. Despite the fact that vitamin A and beta-carotene rich food is generally available, risk groups for low vitamin A supply exist in the western world. It is therefore highly critical to restrict the beta-carotene supply from diet, particularly from sources of beta-carotene with high consumer acceptance such as fortified juices (e.g. "ACE juices") or dietary supplements (e.g. multivitamins for pregnant women). For the part of the population unable to meet vitamin A requirements according to the DACH recommendations, sufficient intake of beta-carotene may be crucial to help improve and maintain adequate vitamin A status and prevention of developmental disorders. At this time it has to be urgently advised against restricting the beta-carotene supply or putting warning labels on beta-carotene fortified products. It is, however, highly recommended to improve the available data on nutrient intakes in Germany, especially for pregnant and breastfeeding women. For them, recommendations to be aware of potential nutrient intake inadequacies might prove useful.

Publication Types:

• Review

Vitamin A in pregnancy: requirements and safety limits

Am J Clin Nutr. 2000 May;71(5 Suppl):1325S-33S

Azaïs-Braesco V, Pascal G.

Most of the functions of vitamin A are mediated through the binding of retinoic acid to specific nuclear receptors that regulate genomic expression. Recent experimental work in transgenic mice showed clearly that normal embryonic development depends on the correct spatial and temporal expression of the receptors in the differentiating cells and on the binding of specific forms of retinoic acid. This implies that the parent compound, vitamin A, is available in adequate forms and quantities. Excessive dietary intake of vitamin A has been associated with teratogenicity in humans in <20 reported cases over 30 y. However, caution must be exercised to avoid unnecessary supplementation of women of childbearing age. Hypovitaminosis A affects millions of women and children worldwide. The main consequence of a poor vitamin A supply during pregnancy is a low vitamin A status at birth and in the next few months. Vitamin A deficiency is strongly associated with depressed immune function and higher morbidity and mortality due to infectious diseases such as diarrhea, measles, and respiratory infections. Vitamin A deficiency is often associated with an increased mother-to-child transmission of HIV-1. The initiation of vitamin A supplementation should be carefully examined in each case according to the risk-to-benefit ratio. The final decision should take into account the estimated vitamin A status of the woman, the availability of vitamin A-rich foods in her diet, and whether supplementation can be supervised.

Publication Types:

• Review

Evaluation of the effect of the use of vitamin supplements on vitamin A intake among (potentially) pregnant women in relation to the consumption of liver and liver products

Eur J Obstet Gynecol Reprod Biol. 1996 May;66(1):17-21

van den Berg H, Hulshof KF, Deslypere JP.

OBJECTIVE: To assess the distribution of dietary vitamin A intake among Dutch women aged 16-50 and among pregnant women, and to evaluate the effect of the use of a vitamin A (1200 RE) containing multivitamin supplement in terms of nutritional and teratogenic risk. STUDY DESIGN: Data from the 2nd Dutch national food consumption survey (1992) were used for calculation of the vitamin A intake among 1725 16-50 year old women and 58 pregnant women. Calculations were performed with and without simulation of the use of a supplement containing 1200 RE vitamin A. RESULTS: Average vitamin A intake, based on a two-day dietary record method, compared quite well with recommended intake levels: 850 RE for the 16-50 year old non-pregnant (NP) women (RDA: 800 RE), and 990 RE for the pregnant (P) women (RDA: 1000 RE), respectively. The use of liver on one of the days under survey resulted in high intakes: 60% of the women in this subgroup exceeded the 'safe upper intake limit' of 3000 RE, while in 23% of the cases intakes were > 7500 RE. Those not consuming liver or liver products on the days under survey had relatively low average intakes [NP (n = 1472): 540 RE; P (n = 46): 720 RE]; about 70% of the non-liver users had intakes below the RDA. Including the daily use of a vitamin A containing multivitamin supplement with 1200 RE resulted in intakes > RDA, while only in 2% (NP), respectively 3% (P) of the cases the 'total' intake exceeded the 3000 RE level, but remained in all cases below 7500 RE/day. serving per day. CONCLUSION: The use of a vitamin A containing (maximum 1200 RE) multivitamin supplement can contribute to a controlled and adequate vitamin A intake and be considered as safe for pregnant women or women who wish to become pregnant, if the consumption of liver is completely avoided and the consumption of liver products is limited to maximum one.

Publication Types:

• Data from the 2nd Dutch national food consumption survey (1992)

Safety of vitamin A: recent results

Int J Vitam Nutr Res. 1998;68(6):411-6

Wiegand UW, Hartmann S, Hummler H.

A still unresolved public health concern is that excessive vitamin A intake, like vitamin A deficiency, possibly causes birth defects not only in animals but also in man. Due to the low incidence of possibly vitamin A-related malformations in man, available data cannot convincingly define the upper safe limit of periconceptional vitamin A intake. Direct human intervention studies are not feasible for ethical reasons. Therefore, a novel approach in addressing this issue was chosen by combining teratogenicity data from a validated animal model with data on systemic exposure to vitamin A and its major metabolites in female volunteers. In a study in pregnant women endogenous plasma concentrations of vitamin A metabolites during early pregnancy ranged from 0.26 to 7.72 ng/ml. Since they did not cause any foetal malformations, retinoid plasma levels in this range can be considered non-teratogenic. Results of a trial in non-pregnant women document that daily oral vitamin A supplements of 4000, 10,000 and 30,000 IU given for 3 weeks were in the range or slightly above the range of endogenous plasma levels seen in early pregnancy. Even after a 3-week treatment with 30,000 IU/day, peak plasma levels of retinoic acid and isotretinoin were within or just slightly above the range of their physiological levels. In cynomolgus monkeys (average weight: 3-4 kg), a NOAEL (no observed adverse effect level) of 7500 IU per kg body weight and a LOAEL (lowest observed adverse effect level) for developmental toxicity of 20,000 IU/kg was found. Considering these results in the cynomolgus monkey, a dose of 30,000 IU/day should also be considered as non-teratogenic in man.

Publication Types:

• Review

Publication Types:

• Review