More than half of women in their 60s take calcium and Vitamin D to boost their bone health and prevent fractures, but now the U.S. Preventive Services Task Force says the popular practice may do nothing at all.
"For many average patients additional vitamin D and calcium may not reduce the risk for an osteoporotic fracture in their lifetime," explains Dr. Glenn Wera.
The task force could not find enough evidence to recommend for or against pre-menopausal women using calcium and Vitamin D or postmenopausal women taking high doses of the supplements.
They did find that postmenopausal women should not take low doses of the pills.
Studies showed no benefit and an increased risk for kidney stones.
"The exception to that are individuals with known osteoporosis or previous fractures with trauma," points out Dr. Thomas Weber.
The Council for Responsible Nutrition, the supplement trade association, responded to the new guidelines, saying they "represent a limited review of the literature leading to controversial conclusions".
"A study like this is an analysis of other analysis and therefore the decision is still not cut in stone and as clear as we might like," notes Dr. Wera.
Doctors agree that the best source of calcium is from your diet; milk, yogurt and leafy greens pack a high calcium punch.
Getting 15 minutes of sun a day and eating fish a few times a week boosts levels of Vitamin D.
But for women whose diets are not adequate, some doctors say they will still recommend the supplements to their patients while they wait for more conclusive research.
Doctors say the most important thing women can do is talk to their doctor about their diet and whether a supplement may be needed.
The U.S. Preventive Services Task Force is made up of a group of independent experts.
They are not affiliated with the government.