Why do older adults face a greater risk of vitamin D deficiency than younger people?
As people age, vitamin D synthesis in the skin declines fourfold, and the kidneys' ability to activate it diminishes, setting the stage for deficiency. Also, many older adults drink little or no vitamin D–fortified milk and get little or no exposure to sunlight. Because individual medical concerns and physiological changes with aging can interfere with vitamin D metabolism, a slightly higher intake of 20 micrograms a day is recommended for those in their 70s and older.
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Which of the following is NOT a small intestinal cell enzyme?
a. Maltase b. Sucrase c. Lactase d. Pectinase
The adult RDA for vitamin B12 (µg/day) is
a. 0.5 b. 1.25. c. 2.4 d. 4.0.
Which disease or disorder is more likely to occur in an individual with excessive body fat?
a. stroke b. osteoporosis c. anemia d. cancer e. Alzheimer's disease
In the process of swallowing, food cannot normally enter the trachea because the ________.
A. tongue directs the flow of food down the esophagus and away from the trachea B. epiglottis covers the larynx C. esophageal sphincter shuts off the passage to the larynx D. trachea does not connect to the esophagus