Recommended Intakes for Vitamin D Are Difficult to Establish Because

question 28

Multiple Choice

Recommended intakes for vitamin D are difficult to establish because

• A) exposure to sunlight varies.
• B) it is present in so many foods.
• C) the body stores such large amounts.
• D) the amount in food varies with the season.

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Definitions:

Descriptive Field Studies

Research that involves observing and describing the behavior of subjects in their natural environment.

Experimental Control

Techniques used in research to minimize the influence of external variables, ensuring that the observed effects are due to the manipulation of the independent variable.

Causal Relationships

The connection between two variables where one variable is found to directly influence or cause an effect on another.

Randomly Assign

The procedure of dispersing subjects into different groups in a study through a process that relies on random chance to ensure each participant has an equal opportunity to be assigned to any given group.