Saudi Press

Saudi Arabia and the world
Monday, Nov 24, 2025

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
Families Accuse OpenAI of Enabling ‘AI-Driven Delusions’ After Multiple Suicides
Riyadh Metro Records Over One Hundred Million Journeys as Saudi Capital Accelerates Transit Era
Trump’s Grand Saudi Welcome Highlights U.S.–Riyadh Pivot as Israel Watches Warily
U.S. Set to Sell F-35 Jets to Saudi Arabia in Major Strategic Shift
Saudi Arabia Doubles Down on U.S. Partnership in Strategic Move
Saudi Arabia Charts Tech and Nuclear Leap Under Crown Prince’s U.S. Visit
Trump Elevates Saudi Arabia to Major Non-NATO Ally Amid Defense Deal
Trump Elevates Saudi Arabia to Major Non-NATO Ally as MBS Visit Yields Deepened Ties
Iran Appeals to Saudi Arabia to Mediate Restart of U.S. Nuclear Talks
Musk, Barra and Ford Join Trump in Lavish White House Dinner for Saudi Crown Prince
Lawmaker Seeks Declassification of ‘Shocking’ 2019 Call Between Trump and Saudi Crown Prince
US and Saudi Arabia Forge Strategic Defence Pact Featuring F-35 Sale and $1 Trillion Investment Pledge
Saudi Sovereign Wealth Fund Emerges as Key Contender in Warner Bros. Discovery Sale
Trump Secures Sweeping U.S.–Saudi Agreements on Jets, Technology and Massive Investment
Detroit CEOs Join White House Dinner as U.S.–Saudi Auto Deal Accelerates
Netanyahu Secures U.S. Assurance That Israel’s Qualitative Military Edge Will Remain Despite Saudi F-35 Deal
Ronaldo Joins Trump and Saudi Crown Prince’s Gala Amid U.S.–Gulf Tech and Investment Surge
U.S.–Saudi Investment Forum Sees U.S. Corporate Titans and Saudi Royalty Forge Billion-Dollar Ties
Elon Musk’s xAI to Deploy 500-Megawatt Saudi Data Centre with State-backed Partner HUMAIN
U.S. Clears Export of Advanced AI Chips to Saudi Arabia and UAE Amid Strategic Tech Partnership
xAI Selects Saudi Data-Centre as First Customer of Nvidia-Backed Humain Project
A Decade of Innovation Stagnation at Apple: The Cook Era Critique
President Trump Hosts Saudi Crown Prince Mohammed bin Salman in Washington Amid Strategic Deal Talks
Saudi Crown Prince to Press Trump for Direct U.S. Role in Ending Sudan War
Trump Hosts Saudi Crown Prince: Five Key Takeaways from the White House Meeting
Trump Firmly Defends Saudi Crown Prince Over Khashoggi Murder Amid Washington Visit
Trump Backs Saudi Crown Prince Over Khashoggi Killing Amid White House Visit
Trump Publicly Defends Saudi Crown Prince Over Khashoggi Killing During Washington Visit
President Donald Trump Hosts Saudi Crown Prince Mohammed bin Salman at White House to Seal Major Defence and Investment Deals
Saudi Arabia’s Solar Surge Signals Unlikely Shift in Global Oil Powerhouse
Saudi Crown Prince Receives Letter from Iranian President Ahead of U.S. Visit
Saudi Arabia’s Crown Prince Begins Washington Visit to Cement Long-Term U.S. Alliance
Saudi Crown Prince Meets Trump in Washington to Deepen Defence, AI and Nuclear Ties
Saudi Arabia Accelerates Global Mining Strategy to Build a New Economic Pillar
Crown Prince Mohammed bin Salman Arrives in Washington to Reset U.S.–Saudi Strategic Alliance
Saudi-Israeli Normalisation Deal Looms, But Riyadh Insists on Proceeding After Israeli Elections
Saudis Prioritise US Defence Pact and AI Deals, While Israel Normalisation Takes Back Seat
Saudi Crown Prince’s Washington Visit Aims to Advance Defence, AI and Nuclear Cooperation
Saudi Delegation Strengthens EU–MENA Security Cooperation in Lisbon
Saudi Arabia’s Fossil-Fuel Dominance Powers Global Climate Blockade
Trump Organization Engages Saudi Government-Owned Real-Estate Deal Amid White House Visit
Trump Organization Nears Billion-Dollar Saudi Real Estate Deal Amid White House Diplomacy
Israel Presses U.S. to Tie Saudi F-35 Sale to Formal Normalisation
What We Know Now: Donald Trump’s Financial Ties to Saudi Arabia
Saudi Arabia’s Ambitious Defence Wish List for Washington: From AI Drones to Nuclear Umbrella
Analysis Shows China, Saudi Arabia and UAE among Major Recipients of Climate Finance Loans
Why a Full Saudi–Israel Normalisation Deal Eludes Trump’s Reach
Trump Presses Saudi Arabia to Normalise Ties with Israel as MBS Prepares for White House Visit
US-Saudi Summit Set for November 18 Seeks Defence Pact and Israel Normalisation Momentum
Comcast CEO Brian Roberts Visits Saudi Arabia Amid Potential Bid for Warner Bros. Discovery
×