I have had blogs about this topic before. Look up “Harm from calcium”on my web-site search option. I agree with most of what is written here, and once again we come up with the power of pharmaceutical companies to promote their wares, even when women don’t necessarily need them. Look at the Independent research. (not pharmaceutical company sponsored)

Calcium Supplementation Does Not Improve Bone Health

Written by Dr. Michael Ruscio, DNM, DC on July 22, 2020

And may increase heart disease risk with Chris Kresser.

Calcium Supplements May Be Harmful

• 10% of American women have osteoporosis, and many women supplement with calcium to avoid risk.
• While dietary calcium is important to prevent osteoporosis, calcium supplements have been shown to increase risk of heart attack or stroke.

Calcium Supplements Don’t Improve Bone Density

• Several studies suggest calcium supplements increase the risk of osteoporosis.
  • A 2012 analysis found calcium intake beyond recommended guidelines provided no benefit at all for hip or lumbar vertebral bone mineral density. [1]
  • A 2007 study published in the American Journal of Clinical Nutrition found that calcium supplements don’t reduce fracture rates in postmenopausal women, and may even increase the rate of hip fractures. [2]
  • Calcium supplements get absorbed into the bloodstream quickly which may lead to distribution into soft tissues instead of into the bones.

• Dietary Calcium Does Increase Bone Density
  • Foods may have a more bioavailable form, perhaps due to more gradual absorption

Calcium Supplements Increase Risk of Cardiovascular Disease

• A 2012 study in the British Medical Journal found that calcium supplements heart attack risk by 140%. [3]
• A 2010 meta-analysis in the British Medical Journal found calcium supplements was associated with a 31% increased risk of heart attack, a 20% increased risk of stroke, and a 5% increase of risk of death from all causes. [4]
• A 2013 study published in the Journal of the American Medical Association found that 1,000mg/day of calcium supplementation was associated with a 20% increase of death from cardiovascular disease. [5]

Cancer and Kidney Stones   

• A Swedish study reported a significantly higher risk of death among men and women with much higher calcium intakes. Some of those deaths were from prostate cancer, and there was also an increase in kidney stones. [6]

Do Vitamin D and Vitamin K2 Reduce Calcium Risk?

• Using Vitamin D and Vitamin K2 with calcium might diminish risk, but we don’t know.
• Some evidence suggests adequate doses of vitamin D and K reduce the dietary need for calcium.
• 700-900mg calcium per day may be adequate.
• Calcium should probably be consumed with vitamin D (or safe sun exposure) and K2 (fermented foods).