ABSTRACT
Micronutrient fortification of staple foods can be an effective strategy to combat micronutrient malnutrition. When planning on fortification, challenges faced include the collection of essential information on population food and nutrient intake patterns, as well as the use of this information in a method to select appropriate fortification levels. A symposium was organized aimed at discussing the existing approaches to set effective and safe micronutrient fortification levels and to outline the challenges and needs in this area. Two different approaches to establish effective and safe fortification levels for food fortification were presented. In the first approach, the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) are used as cut-points in the micronutrient intake distribution to evaluate and simulate effective and safe micronutrient intakes. This was exemplified by challenges encountered in Guatemala and Cameroon towards unequal vitamin A intake distribution and the impact of the food vehicle choice. Secondly, the risk-benefit approach was presented as an approach in which risks and benefits of micronutrient intakes can be quantified and balanced in order to optimize fortification benefits with the least risks and to allow decision making. This was illustrated by a case on folic acid fortification in The Netherlands. Irrespective of the approach, food and nutrient intake data are required to identify potential vehicles for fortification, quantify the nutrient gap to be addressed, and set the appropriate level of fortification based on consumption pattern. Such information is rarely available to the quality and extent ideal to set fortification levels and requires regular updating, as exemplified in the case of sugar fortification in Guatemala. While the EAR cut-point method can be used to determine the proportion of the population meeting their required and safe nutrient intakes and set goals, riskbenefit assessment may offer an answer to commonly-asked questions as to whether, and at which levels, the benefits of increasing micronutrient intakes outweigh the risks.
ABSTRACT
Objectives: It has been reported that low vitamin B12 status and high serum folate is associated with anemia and cognitive impairment. However, few data are available on neurophysiological outcomes, such as peripheral neurophysiology. The objective was to assess associations between folate, B12 and sensory peripheral nerve conduction in Chilean elderly exposed to folic acid fortification. Methods: The average of the left and right distal sensory conduction latency of the sural nerve, and conduction velocity of the right peroneus nerve were measured in 159 community-dwelling older Chilean. Serum folate, B12, Hcy, MMA, and holoTC were determined. B12 status was defined based on: w=log_10 (holoTC*B12)/(MMA*Hcy)-(age factor) (Fedosov SN, Clin. Chim. Acta. 2013). Nerve conduction, folate and B12 status were divided into tertiles. Results: Age was 70-78y (57% women). 62.9%, 10.7% and 26.4% were classified as having B12 adequacy (w>-0.5), transitional status (-1.5< w<-0.5) and deficiency (w<-1.5) respectively, while 15.1% presented high folate (>45.3 nmol/L). Nerve conduction velocity of the right peroneus nerve positively correlated with B12 status (r=0.21, p<0.05). In the highest tertile of both B12 (w) and folate only 6% were in lowest tertile of sural nerve conduction vs. 31.5% (p<0.001) with low B12 and high folate. In the highest tertile of both B12 (w) and folate 25% were in lowest tertile of peroneal nerve conduction velocity as compared with 63.2% with low B12 and high folate (p<0.001). Conclusions: Elderly with both high B12 and folate status were less likely to have poor sensory peripheral nerve conduction than those with low B12 and high folate.
ABSTRACT
During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poorfolate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.