Question

vitamin d is necessary for this process. most americans ingest too little calcium and vitamin d in their diet. in a study of individuals 18-25 years old, it was shown that the majority had significantly low levels of calcium in their blood. when these individuals received daily supplements of 1,500 mg of calcium and 400 units of vitamin d, their blood calcium levels increased to normal levels. if insufficient levels of calcium and vitamin d are supplied by the diet, dietary supplements should be taken to avoid osteoporosis.estrogen hypothesisestrogens, hormones produced primarily in the ovaries in women and, to a much lesser degree, in the adrenal glands in both sexes, and androgens, produced in the testes in men, are required for the deposition of calcium into bones. androgen levels in men remain relatively constant throughout life; estrogen levels in women slowly decline after the onset of menopause (the time when a womans ability to reproduce ends), which usually occurs between the ages of 45 and 55. as a result, the bones of postmenopausal women lose calcium.scientists compared the bone density of 4 groups of postmenopausal women. each group took a dietary supplement. the results are shown in the table.| group | supplements | change in bone density || ---- | ---- | ---- || a | estrogen | +2.3% || b | 500 mg calcium | -1.0% || c | estrogen + 500 mg calcium | +2.3% || d | sugar | -1.0% |exercise hypothesislack of exercise results in calcium loss from bones, whereas regular weight-bearing exercise can increase bone density. one study showed that 8 weeks of weight training added calcium and hardened bones in both postmenopausal women and men over the age of 45. since body weight is supported by water, 8 weeks of swimming had no effect on bone density. both groups followed the same high-calcium diet. vitamin d intake was not measured!4 multiple choice 3 pointswhich of the following is a criticism that supporters of the dietary hypothesis would make of the experimental results cited in the exercise hypothesis?- osteoporosis is more common in premenopausal women than in postmenopausal women.- estrogen supplements should have been given to each group of individuals.- too much calcium was added to the diets of the test subjects in both groups.- blood vitamin d levels in the two groups were not monitored.6 multiple choice 3 pointshow would supporters of the dietary hypothesis explain the results for group b in the experiment cited in the estrogen hypothesis?- insufficient calcium was added to the diet to increase bone density.- too much estrogen was added to the diet of this group to affect bone density.- estrogen supplements should have been taken to increase bone density.- vitamin d supplements should not have been taken by this group.7 multiple choice 3 pointsthe experiments cited in the estrogen hypothesis and in the exercise hypothesis are similar in that each- test subject was given a calcium supplement.- test subject was given an estrogen supplement.- test subject was given a vitamin d supplement.- woman tested was postmenopausal.

Explanation:

Question 4

The Dietary Hypothesis focuses on dietary calcium/vitamin D intake as key for bone health. To critique the Exercise Hypothesis's experimental results, a point that undermines its methodology related to dietary controls works. The Exercise Hypothesis study used a high-calcium diet but didn't monitor vitamin D, which is critical for calcium absorption—this gap supports the Dietary Hypothesis's critique, as unmeasured vitamin D levels could confound the exercise-bone density link.

The Dietary Hypothesis centers on calcium (and vitamin D) intake as the main driver of bone density. Group B only took 500 mg calcium and had a bone density decrease. From this hypothesis's view, this calcium amount was too low to counteract postmenopausal bone loss and increase density.

Looking at both experiments: the Estrogen Hypothesis study gave calcium supplements to some groups, and the Exercise Hypothesis study had all subjects on a high-calcium diet (a form of calcium intake/supplement). The other options are incorrect: only the Estrogen study used estrogen supplements, only the first (vitamin D) study used vitamin D supplements, and the Exercise study included men over 45 too.

Answer:

D. Blood vitamin D levels in the two groups were not monitored.

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Question 6