Which one of the following is the study of choice for determining the state of vitamin B12 deficiency in Australia?
A) Cohort study. B) Case-control study. C) Randomized controlled trial (RCT). D) Cross-sectional study. E) Case series.
D) Cross-sectional study
A cross-sectional study is the study of choice when assessing the prevalence of a condition or health-related state â such as vitamin B2Â deficiency â in a specific population at a particular point in time.
In Australia, if the goal is to determine how widespread vitamin D deficiency is, a cross-sectional design provides a snapshot, allowing for analysis of:
Population characteristics (age, gender, region, season)
Risk factors (e.g., sun exposure, diet)
Correlation with serum vitamin D levels
Why other options are not correct:
A) Cohort study â Good for studying incidence and identifying risk factors over time, but not ideal for assessing current prevalence.
B) Case-control study â Used to examine associations between exposures and rare diseases, not to measure prevalence.
C) Randomized controlled trial (RCT) â Best for evaluating interventions (e.g., vitamin D supplementation), not for measuring deficiency in a population.
E) Case series â Descriptive and involves a small group of individuals with a condition; cannot determine population-level prevalence.
