Saudi Press

Saudi Arabia and the world
Friday, Apr 10, 2026

Vitamin D and Calcium Supplements: A Double-Edged Sword?

An Academic Evaluation of Their Role in Preventing Osteoporosis and Cancer.
On March 12, Dr. F. Perry Wilson delivered a lecture entitled "Vitamin D Supplements: A Double-Edged Sword?" on the medical site "Medscape." The presentation was spurred by the long-term results of a comparative study on the consumption of "Calcium/Vitamin D (CaD) supplements" by women for the prevention of bone fractures and osteoporosis, as well as colon cancer. This involved taking pills containing 1000 mg of calcium carbonate with 400 international units of vitamin D, compared to taking a placebo.

The study, published in the "Annals of Internal Medicine" on March 12, 2024, under the title: "The Long-term Effect of Randomized Calcium and Vitamin D Supplement Intake on Health in Older Women," provided critical insights.

Dr. Wilson, an Associate Professor of Medicine (Nephrology) and Public Health (Epidemiology of Chronic Diseases) at Yale School of Medicine, is also the creator of the popular online course "Understanding Medical Research: Your Facebook Friend is Wrong," and author of "How Medicine Works and When It Doesn't: Finding Trustworthy Health Information and Staying Healthy." He emphasizes the importance of seeking accurate and beneficial medical information for preserving health and preventing illnesses.

Medical Follow-up Analysis

The backdrop to this recent study, which is a “post-hoc” analysis of long-term medical follow-ups within the "Women's Health Initiative (WHI Study)" supported and funded by the "National Institutes of Health (NIH)" since 1991 across 40 medical centers in the United States, involves more than 36,000 postmenopausal women (aged between 50 and 79 years at the start of the study) consuming calcium and vitamin D supplements.

Initially hypothesized in the 1990s that women taking a combination of calcium and vitamin D would have a reduced risk of hip fractures and other fractures, along with lower incidences of breast, colon, and rectal cancers, the initial results, released after seven years into the study, noted a "slight" improvement in hip bone density but no significant decrease in hip fractures. Additionally, there was no effect on the incidence of colon and rectal cancer or breast cancer but an observed increase in the risk of kidney stones.

Dr. Cynthia Thomson, from the "Mel and Enid Zuckerman School of Public Health" at the University of Arizona, and her colleagues conducted this "post-hoc" analysis, which focused on two outcomes hinted at but not statistically confirmed in other vitamin D and calcium studies: a reduction in cancer risk and a possible increase in heart disease risk.

The new study's results (after long-term follow-up since 1991) revealed a 7% reduction in cancer incidences, with a parallel and equal increase in heart disease occurrences. The researchers summarized, "Calcium and vitamin D supplements appear to reduce cancer deaths and increase cardiovascular deaths after more than 20 years of postmenopausal women's follow-up, without any positive effect on deaths from all causes."

Varied Results of Supplements

In his presentation, Dr. Wilson began by saying, "In all clinical research, I believe there is no molecule with stronger associative data and weaker causative data than (the case of taking) vitamin D supplements." He cited low blood levels of vitamin D linked to increased risks of heart disease, cancer, falls, COVID, dementia, and more. However, randomized trials on vitamin D supplementation, which could prove a causative link to these outcomes, often yield negative results.

He highlighted a potential shift toward viewing normal vitamin D levels as an indicator of a person's healthy lifestyle factors, such as regular exercise, outdoor activities, and a balanced diet rather than the supplement intake itself.

Concluding Remarks

The Mayo Clinic summarizes that while calcium is critical for bone and cardiovascular health, vitamin D is essential for the body to absorb calcium. While food remains the best source for calcium and vitamin D, supplements may be necessary in specific situations where dietary intake is insufficient. However, the healthcare community emphasizes moderation and the potential risks of excessive supplementation, highlighting the importance of consulting healthcare professionals for personalized advice.
Newsletter

Related Articles

Saudi Press
0:00
0:00
Close
Gulf States Assess Prospects of U.S.-Iran Truce as Regional Stability Efforts Intensify
South Korea Resumes Honey Exports to Saudi Arabia Following Sanitary Approval
Saudi Arabia Carries Out Sentences in Eastern Province Following Security Convictions
Saudi Sovereign Wealth Fund Backs King Street’s Regional Credit Strategy
Saudi Arabia Secures World Cup Return as Egypt Celebrates Landmark Qualification
Iran and Saudi Arabia Intensify Diplomatic Engagement Amid Regional Tensions
Russia and Saudi Arabia Open Visa-Free Travel Corridor for Citizens
Saudi Oil Output Capacity Reduced by 600,000 Barrels Per Day Amid Regional Conflict
Saudi Arabia Suspends Operations at Select Energy Sites as Precautionary Measure
Saudi Arabia Halts Operations at Multiple Energy Facilities Amid Heightened Tensions
Global Markets Jolt as Iran Signals Ceasefire Breakdown and Rising Regional Tensions
King Street Aligns with Saudi Sovereign Wealth Fund to Expand Alternative Investments in Middle East
Attack on Saudi Arabia’s Jubail Petrochemical Hub Raises Global Supply Concerns
Debate Emerges Over Saudi Strategic Decisions as Gulf Cooperation Council Dynamics Come Into Focus
Saudi Arabia Expands Full Workforce Localisation to 69 Professions in Major Labour Reform
Emerging Alliance of Pakistan, Turkey, Egypt and Saudi Arabia Signals New Regional Power Dynamic Amid Iran Conflict
Iran Linked to Strikes Across Gulf States Following Refinery Attack Escalation
Saudi Arabia Voices Concern Over Fragile US–Iran Ceasefire Stability
Starmer Warns Sustained Effort Needed to Ensure US–Iran Ceasefire Holds
Saudi Arabia’s Key East-West Oil Pipeline Targeted Following Ceasefire Announcement
Iran Targets Saudi Arabia’s East-West Oil Pipeline in Escalating Regional Tensions
Trump Warns of Civilizational Stakes as Iran Halts Negotiations
Saudi Companies Expand Remote Work Measures Ahead of Iran-Related Security Concerns
Iran Warns of Strikes on Saudi Energy Infrastructure if US Targets Its Facilities
Iran Urges Civilians to Form Human Shields Around Nuclear Sites as Diplomatic Deadline Approaches
Saudi Arabia Raises Oil Prices to Record Premiums Amid Supply Pressures Linked to Iran Conflict
Key Saudi-Bahrain Causeway Closed Amid Heightened Security Concerns Linked to Iran
Formula One Calendar Gap Explained as Fans Await Next Grand Prix
Growing Strain on the Petrodollar System Comes Into Focus Amid Iran Conflict
Reported Strike on Saudi Arabia’s Jubail Complex Raises Global Energy Supply Concerns
FedEx Introduces New Digital Tool to Streamline Imports into Saudi Arabia
Iran Claims Strike on Saudi Arabia’s Jubail Petrochemical Complex Amid Rising Regional Tensions
Taiwan to Source Oil Shipments from Saudi Arabia’s Red Sea Ports
Saudi Arabia Evacuates Riyadh Financial District as Precaution Amid Regional Tensions
Saudi Arabia Balances Ambitious Economic Vision Amid Regional Tensions and Financial Pressures
Budget Saudi Arabia Reports Strong Full-Year 2025 Financial Performance
Saudi Arabia Expands Investment in Capcom With Stake Reaching Six Percent
Saudi Arabia Assesses Significant Economic Impact From Regional Conflict Involving Iran
US Beef Secures Expanded Market Access in Saudi Arabia
Jordan and Saudi Arabia Declare Absolute Solidarity in Response to Iranian Threats
Saudi Arabia Raises Oil Prices to Record Premium Amid Strong Market Demand
California’s Salton Sea Emerges as Strategic Lithium Hub for Clean Energy Future
Iranian Drone Strike on US Embassy in Saudi Arabia Reportedly Targeted Intelligence Facility
Saudi Deputy Foreign Minister Meets French Embassy Official to Strengthen Bilateral Engagement
Saudi Arabia Calls on United States to Seize Strategic Opportunity to Reshape Middle East
Dating Apps Surge in Saudi Arabia as Social Norms Rapidly Evolve Among Youth
Saudi Arabia Detains Over Fourteen Thousand Illegal Residents in Week-Long Enforcement Drive
Saudi Foreign Minister Engages in Diplomatic Talks with Pakistan, Kuwait and Latvia on Regional Developments
Saudi Arabia Intercepts Cruise Missile as Regional Tensions Intensify
Saudi Stock Market Edges Higher as Tadawul Index Records Modest Gain
×