In the paper, published in a supplement to The Journal of Nutrition experts in the fields of medical and nutritional science clarify current knowledge on beta-carotene, focusing specifically on its physiological function, supply situation, and intake recommendations.
The experts, led by Prof. Tilman Grune from University of Hohenheim met at a conference organized by the Institute of Biological Chemistry and Nutrition, at the University of Hohenheim, Stuttgart. The conference was cosponsored by DSM Nutritional Products Ltd
The consensus conference placed special emphasis on the pro-vitamin A function of beta-carotene and the role of beta-carotene in the realization of the required total vitamin A intake in both developed and developing countries.
"As the current beta-carotene intakes from diet do not fill the gap of low consumptions of dietary sources for pre-formed vitamin A in large parts of the population in Europe, the US and Asia, foods fortified with beta-carotene and dietary supplements are important contributors to the daily supply of vitamin A,” said DSM spokesperson Peter Engel.
Pro-vitamin
The main function of beta-carotene is as a pro-vitamin A. Prof. Grune and colleagues stated that a role of beta-carotene in fulfilling the recommended intake for vitamin A is apparent from a variety of studies
The experts also suggested that there is evidence that beta-carotene has effects that go beyond the established pro-vitamin A function. However, they added that these effects have not yet been proven in humans.
According to the scientists there is no difference between naturally occurring and chemically synthesized beta-carotene.
Vitamin deficiency
Dietary beta-carotene intake is reported to vary widely, with unequal distribution throughout the population.
The experts said that based on previous research it is evident that “parts of the world’s population do not meet the recommendation for vitamin A intake with dietary sources of pre-formed vitamin A.”
They added that in the U.S and the U.K, the majority of people consume between one and two milligrams per day, whilst the intake of pre-formed vitamin A in large parts of the Asian population is very low.
Based on recent data including food composition and data from national surveys, the authors concluded that intake of pre-formed vitamin A is inadequate “in a substantial part of the general population.”
“Young individuals are at increased risk of developing at least a mild form of vitamin A deficiency due to their very low intakes of total vitamin A. More importantly, physiological needs for vitamin A increase during pregnancy and lactation,” they stated.
Recommendations
The researchers noted that although fruits and vegetables contribute to the daily vitamin A supply, the recommended beta-carotene intake of 2 to 4 mg per day is not achieved in the general population.
According to the experts, the basic need for beta-carotene in its pro-vitamin A function is defined by the existing gap between pre-formed vitamin A intake and recommendations for total vitamin A intake.
“To fill the gap between the low intakes from sources containing pre-formed vitamin A, adequate amounts of pro-vitamin A must additionally be supplied,” they added.
Grune and co concluded that the current recommended amounts of consumed beta-carotene should be increased to 7 mg per day, “to ensure that at least 95 percent of the population consumes the recommended intake of total vitamin A.”
Importance
DSM spokesperson Engel added that recent mainstream media reporting of a research suggesting high doses of beta-carotene are associated with increased risk lung cancer in high risk groups of smokers, has caused many people to become “needlessly wary and distrustful of supplements and fortified foods”. Engel said that such issues exacerbate the problem of insufficient vitamin intakes.
“Thus, it is very important that international experts now have emphasized that beta-carotene is indispensable as a safe source of vitamin A," he added.
Source: The Journal of Nutrition
Published ahead of print, doi: 10.3945/jn.109.119024
“b-Carotene Is an Important Vitamin A Source for Humans”
Authors: T. Grune, G. Lietz, A. Palou, A.C. Ross, W. Stahl, G. Tang, D. Thurnham, S. Yin, H.K. Biesalski