If you take iron supplements, make sure to take them separately from calcium supplements, which can interfere with their absorption.

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It also concludes that calcium supplements are not needed.

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If they can't, then he recommends calcium supplements.

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Cliff Rosen, past president of the American Society for Bone and Mineral Research, agreed that there isn't much data showing calcium-and-vitamin-D supplements can prevent bone fractures.

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To combat this, scientists recommend that pregnant women ensure that they eat enough calcium-rich foods like milk, or else take supplements.

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Doctors recommend women figure out with their primary doctors how much calcium and vitamin D they are getting from food and either make adjustments to their diets or add separate supplements of both nutrients to get to recommended daily intake of each.

WSJ: Vitamin D and Calcium Supplements May Not Stop Fractures