Expert opinion
The Mandatory Fortification of Staple Foods with Folic Acid
16 May 2011
The mandatory fortification of staple foods with folic acid to prevent neural tube defects was introduced in the USA in 1998.
01 December 2011
Big parts of the female population may have limited abilities to absorb beta-carotene and convert it into vitamin A due to genetic variations, a new UK study suggests.
The study investigated the effects of four common genetic variations (single nucleotide polymorphisms, SNPs) of the enzyme converting beta-carotene to vitamin A (retinal) in 28 female participants with a mean age of 20 years (1). The study results showed that three of the four SNPs significantly reduced the beta-carotene conversion by up to 59%. Furthermore, large variations in frequency of the SNPs were detected among 11 different ethnic groups, with frequencies varying from 43 to 100%.
The researchers concluded that a range of SNPs can reduce the effectiveness of using plant-based provitamin A carotenoids, such as beta-carotene, to increase vitamin A status among at-risk population groups. This effect may vary depending on ethnic origin. Thus, people with reduced ability to convert provitamin A sources into active vitamin A could be susceptible to wide-ranging health risks. They considered this to be especially important since recent research indicates that approximately 45% of all Europeans possess a gene variant that restricts the amount of beta-carotene their bodies can utilize and convert into vitamin A. If the gene-related restrictions on the utilization of beta-carotene would be taken into account, then the daily recommendation might need to be significantly higher, or alternatively, these individuals might have to increase their preformed vitamin A intake from animal sources or supplements.
Recently, international carotenoid experts have stated in a consensus answer that beta-carotene is indispensable as a safe source of vitamin A (2). As the intake of preformed vitamin A from animal products is not sufficient in parts of the population in Europe, the United States, and Asia, beta-carotene is considered to have an important function in providing an adequate supply of total vitamin A.
Vitamin A is essential for normal growth and development, immune system, vision, and other functions in the human body. Because humans are unable to synthesize vitamin A they must consume diets with preformed vitamin A or provitamin A carotenoids. Upon absorption, provitamin A carotenoids are readily converted to vitamin A by the enzyme beta-carotene 15,15’-monoxygenase (BCMO1). Recent research showed that two common SNPs within the BCMO1 coding gene region cause reduced catalytic activity of the enzyme, confirming that genetic variations contribute to low beta-carotene utilizations.
Vitamin A deficiency is a serious public health problem that mostly affects pregnant and lactating women and preschool children, with an estimated 250 million at risk of developing vitamin A deficiency disorders (3). A majority of the vitamin A requirements for the population in the United Kingdom, for example, are not met by dietary intake of preformed retinol, and 15% of young individuals aged 19–24 years have a total vitamin A intake below the lower recommended nutrient intake level (4).
16 May 2011
The mandatory fortification of staple foods with folic acid to prevent neural tube defects was introduced in the USA in 1998.
23 August 2013
According to a new US study patients with the syndrome chronic daily headache may benefit from higher intakes of omega-3 fatty acids and lower consumption of omega-6 fatty acids.
16 August 2013