Should you Take Calcium and Vitamin D Supplements Together?

Should you Take Calcium and Vitamin D Supplements Together?

By: Holly L. Thacker, MD • Posted on May 07, 2024

New research shows taking calcium and vitamin D supplements together may reduce the risk of dying from cancer but raise the mortality risk for cardiovascular disease.

Postmenopausal women have a high risk of developing osteoporosis because bone loss density when estrogen drops during this time. Osteoporosis has been linked with low calcium levels, and vitamin D helps with calcium absorption, so many postmenopausal women take both supplements. 

Why are postmenopausal women encouraged to take calcium and vitamin D?

All people need calcium and vitamin D. The historical reason postmenopausal women have been encouraged to ingest both is because 1 in 2 women develop osteoporosis due to estrogen loss at menopause. Estrogen and vitamin D help the gut absorb calcium. 

Vitamin D is not a vitamin at all, but it is a pro-sterol hormone. Many people in Northern latitudes are vitamin D deficient. The 400IU "RDA" (recommended daily amount) of vitamin D3 is not based on science, but rather that is how much mothers would give their children to prevent rickets in childhood.

What does this research suggest about taking these supplements together? 

Calcium supplements do not need to be taken IF one ingests enough calcium from the diet and has adequate vitamin D levels.

Would this study change any current recommendations for taking calcium and vitamin D together, or is the risk of CVD too slight to warrant any changes? 

This study used too much calcium if one was also ingesting calcium in their diet, and likely not optimal vitamin D intake for most adult women. It also did not include Vitamin K2/MK-7 which drives calcium into the bone and not the arterial vasculature.

Do we have any evidence to suggest that taking calcium and vitamin D together causes any health problems, or is there only an association with increased CVD risk? (In other words, can we really say anything definitively about this study?) 

There appears to be a very slight association with too much calcium intake and arterial disease and an association with reduced cancer risks (and other diseases) with vitamin D.

What's the takeaway for postmenopausal readers who may be anxious about their supplement routines? 

Postmenopausal women should be concerned about the risks of hormone deficiency and should be cognizant that excessive calcium supplementation should not be a substitute for preventing postmenopausal bone loss. All adults (and children) should avoid vitamin D deficiency. Those pushing the intake of calcium and vitamin D should also eat a diet rich in Vitamin K2/MK7 or take a supplement if needed. I frequently recommend Micro Ingredients Vitamin D3 + vitamin K2/MK7 supplement to my patient to support bone, teeth, immune, heart and joint health.

For more information on vitamin D, I recommend listening to my Speaking of Women’s Health podcast episode Why Women Need Vitamin D.

Be Strong, Be Healthy, Be in Charge!
Holly L. Thacker, MD

About Holly L. Thacker, MD, FACP

Holly L. Thacker, MD, FACP is nationally known for her leadership in women’s health. She is the founder of the Cleveland Clinic Specialized Women’s Health Fellowship and is currently the Professor and Director of the Center for Specialized Women’s Health at Cleveland Clinic and Lerner College of Medicine at Case Western Reserve University. Her special interests are menopause and related medical problems including osteoporosis, hormone therapy, breast cancer risk assessment, menstrual disorders, female sexual dysfunction and interdisciplinary women’s health. Dr. Thacker is the Executive Director of Speaking of Women’s Health and the author of The Cleveland Clinic Guide to Menopause.

Related Articles