Using Technology Advancements to Improve Nutritional Assessments
Nutrient intakes are routinely used to estimate nutrient status. Because of day-to-day variability in eating patterns, the number of days of food intake data required varies tremendously by nutrient. Food intake must be recorded for 5-16 days to estimate the true average vitamin B intake for a group of individuals and greater than 19 days for vitamins A and C. Most nutrient intake studies are not this comprehensive.
Ideally, nutritional status is assessed using objective measures (biomarkers such as serum vitamin D concentrations) which are related with functional outcomes (muscle strength, immune function). Barriers to the development of biochemical or clinical indices of nutritional status have been cost and convenience. It is costly to get people to clinics where biological samples (blood, urine, tissue) can be obtained. Biological samples require carefully processing to preserve sample integrity. These are researcher considerations. Participants/subjects/volunteers find it inconvenient to schedule appointments and travel to a clinical facility and don’t enjoy have their veins poked.
However, technological advances are changing this landscape. For example, vitamin B12 status can now be cost-effectively assessed in dried blood spot samples. Using blood from a finger (or heel) prick is much less invasive and can be conducted in nonclinical settings without the need for venipuncture. Samples can be stored at -80C for at least 1 year without degradation.
Capillary blood can also be used to assess serum retinol concentrations; avoiding the need for a trained phlebotomist. Vitamin D concentrations [25(OH)D3 and 25(OH)D2] can be accurately measured in dried blood spots which have been stored for up to 22 years. While the need for LC/MS/MS analysis is not simple, the consumer experience is much less invasive. Using finger prick sampling techniques coupled with validated analytical procedures improves nutritional assessment above that achieved with dietary records.
Faster, cheaper methods does not circumvent the need for consensus on suitable biomarkers, standards, and analytical methods. However, the availability of cost effective, non-invasive, field-applicable tools, and their adoption, should improve nutritional assessment of individuals and populations.
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