Water Soluble Vitamin Research
The research activities of the water
soluble vitamin laboratory are directed towards supporting the mandate
of Health Canada. Various aspects of these essential micronutrients
including their levels and availability in foods, their interactions
with other dietary components and their roles in health and disease
are investigated. One area of current research is the updating of
older methods for measuring water soluble vitamins. Newer methods
and modifications of old ones are often more precise or accurate
and permit updating or adding vitamin values for existing or new
food products to nutrient data files. Use of high performance liquid
chromatography methodology permits very accurate separation and
detection of different forms and derivatives of individual vitamins
found in foods and biological tissues. Microplate modification of
standard microbiological assay methods that measure growth response
of dependent microorganisms to different levels of particular vitamins
extracted from foods, decreases reagent requirements and increases
the number of samples that can be measured. Current investigations
are looking at vitamin levels in infant formulas and fortified food
products used throughout Canada and in unique foods that are potentially
important sources of nutrients for indigenous people in Canada.
Results obtained contribute to the Canadian Nutrient
File and other data bases that are used in nutrition surveys,
and contribute to policy decisions and advice concerning vitamin
requirements, fortification and recommended intakes. Accurate determination
of food vitamin levels are also required to check the need for,
efficacy and safety of fortification practices. The recent requirement
to fortify cereal-based products with folate to increase intake
levels of women at risk of becoming pregnant and decrease risk of
occurrence of neural tube defects such as spina bifida demonstrates
one area where accurate measure of food vitamin levels is required.
Interactions of different nutrients and other food components with
particular vitamins are areas of ongoing research. Using animal models,
the influence of folic acid and vitamin B12 and different kinds of
dietary fats on aspects of lipid (lipoprotein profiles, lipid
peroxidation) and on amino acid (transmethylation, transsulfuration)
metabolism are currently being studied. Information derived could
contribute to knowledge about metabolic mechanisms and suggest dietary
manipulations to influence independent risk factors for coronary heart
disease and atherosclerosis including serum levels of different forms of
cholesterol and homocysteine. Investigation into the role of dietary
fibre on gut bacterial synthesis and availability of folate could
suggest alternate means of increasing folate status in target groups
while decreasing long term, higher level exposures of potential risk
groups such as the elderly and children. Recommendations and policies
derived from such studies contribute to the health of all Canadians.
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