A systematic review of medical journal articles affirmed a strong association between higher serum vitamin D levels and a lower risk of bladder, breast, colon, endometrial, esophageal, gallbladder, kidney, ovarian, pancreatic, rectal, stomach and vulvar cancers, as well as Hodgkin’s and non-Hodgkin’s lymphomas. The review also uncovered lower risks of metastasis and mortality from cancer in association with higher levels of vitamin D. Author Sunil J. Wimalawansa, MD, of the Cardio Metabolic and Endocrine Institute in North Brunswick, New Jersey, concluded that while a 25-hydroxyvitamin D level of 20 nanograms per milliliter (ng/mL) is sufficient for the health of bone and muscle, levels greater than 40 ng/mL significantly reduced cancer risk and mortality, and more than 50 ng/mL is associated with even greater protection.
Wimalawansa suggested that negative results of studies that used less than 5,000 IU vitamin D per day or those that evaluated a serum level of less than 40 ng/mL should be interpreted with caution since these amounts and levels are less than optimal for cancer risk reduction. “While many observational studies support vitamin D’s protective role in incidents and deaths from cancer, some recent mega-randomized, controlled trials have failed to demonstrate this,” he noted. “The latter is primarily due to critical study design flaws, like recruiting vitamin D-sufficient subjects, inadequate dosing, short durations, and biased designs…Consequently, conclusions from these cannot be relied upon.”
He concluded that vitamin D exerts system-wide beneficial effects beyond bone health and significantly affects immune regulation, gene expression and disease prevention through several mechanisms. The current review affirmed the importance of maintaining optimal serum vitamin D concentrations of 40 or 50–80 ng/mL to fully realize these beneficial effects. Dr. Wimalawansa suggested 5,000 IU as a sufficient daily dose of the vitamin.
The systematic review cited 416 articles, including those that reported findings from observational studies, epidemiological investigations, randomized trials, and mechanistic or hypothesis-generating studies relevant to the analysis of the association between vitamin D and cancer. The article was published July 16, 2025, in the journal Nutrients.
Apply What You've Learned: Vitamin D and Cancer
Research has revealed a number of mechanisms for vitamin D against cancer. Vitamin D helps prevent cancer cell growth, promotes cancer cell death, blocks the formation of blood vessels that deliver nutrients to cancer and reduces metastasis.
In addition to increasing the risk of cancer, vitamin D insufficiency and deficiency are also associated with negative effects associated with the disease, including infection, pain, depression and diminished quality of life.
While exposure to ultraviolet rays increases vitamin D in the body, the American Academy of Dermatology recommends against obtaining vitamin D from sunlight, sun lamps or tanning beds due to the increased risk of skin cancers associated with these methods.
Vitamin D is present in foods such as fatty fish, egg yolks, mushrooms, fortified dairy products and other fortified foods. Vitamin D can also be added to the diet in the form of vitamin D2 or D3. Regular blood testing for serum 25-hydroxyvitamin D levels can help determine whether the amount of vitamin D we consume is sufficient to obtain optimal levels.
Are you Taking Vitamin D?
If you're not taking Vitamin D, you can order from us at this link or pick it up in our office:
joyfullivingservices.com/life-extension.html
Check your blood test results. Most doctors don't check for Vitamin D during the normal annual exam. Ask your doctor to check your Vitamin D level and make sure it's up at 70. Most people are low and down in the 30's.
Let me know if you have any questions.
Brenda
Brenda R. Generali, CCII3, Naturopath
President and Founder, Joyful Living Services: http://www.joyfullivingservices.com
IIPA 2024 Professor O'Brian Educational Mentoring Award: https://www.iridologyassn.org/
IIPA 2021 Instructor of the Year: https://www.iridologyassn.org/
Certified Comprehensive Iridology Instructor Levels I, II, III: https://www.iridologyassn.org
Phones: (O) 530-878-1119 or (C) 530-368-0918
Wimalawansa suggested that negative results of studies that used less than 5,000 IU vitamin D per day or those that evaluated a serum level of less than 40 ng/mL should be interpreted with caution since these amounts and levels are less than optimal for cancer risk reduction. “While many observational studies support vitamin D’s protective role in incidents and deaths from cancer, some recent mega-randomized, controlled trials have failed to demonstrate this,” he noted. “The latter is primarily due to critical study design flaws, like recruiting vitamin D-sufficient subjects, inadequate dosing, short durations, and biased designs…Consequently, conclusions from these cannot be relied upon.”
He concluded that vitamin D exerts system-wide beneficial effects beyond bone health and significantly affects immune regulation, gene expression and disease prevention through several mechanisms. The current review affirmed the importance of maintaining optimal serum vitamin D concentrations of 40 or 50–80 ng/mL to fully realize these beneficial effects. Dr. Wimalawansa suggested 5,000 IU as a sufficient daily dose of the vitamin.
The systematic review cited 416 articles, including those that reported findings from observational studies, epidemiological investigations, randomized trials, and mechanistic or hypothesis-generating studies relevant to the analysis of the association between vitamin D and cancer. The article was published July 16, 2025, in the journal Nutrients.
Apply What You've Learned: Vitamin D and Cancer
Research has revealed a number of mechanisms for vitamin D against cancer. Vitamin D helps prevent cancer cell growth, promotes cancer cell death, blocks the formation of blood vessels that deliver nutrients to cancer and reduces metastasis.
In addition to increasing the risk of cancer, vitamin D insufficiency and deficiency are also associated with negative effects associated with the disease, including infection, pain, depression and diminished quality of life.
While exposure to ultraviolet rays increases vitamin D in the body, the American Academy of Dermatology recommends against obtaining vitamin D from sunlight, sun lamps or tanning beds due to the increased risk of skin cancers associated with these methods.
Vitamin D is present in foods such as fatty fish, egg yolks, mushrooms, fortified dairy products and other fortified foods. Vitamin D can also be added to the diet in the form of vitamin D2 or D3. Regular blood testing for serum 25-hydroxyvitamin D levels can help determine whether the amount of vitamin D we consume is sufficient to obtain optimal levels.
Are you Taking Vitamin D?
If you're not taking Vitamin D, you can order from us at this link or pick it up in our office:
joyfullivingservices.com/life-extension.html
Check your blood test results. Most doctors don't check for Vitamin D during the normal annual exam. Ask your doctor to check your Vitamin D level and make sure it's up at 70. Most people are low and down in the 30's.
Let me know if you have any questions.
Brenda
Brenda R. Generali, CCII3, Naturopath
President and Founder, Joyful Living Services: http://www.joyfullivingservices.com
IIPA 2024 Professor O'Brian Educational Mentoring Award: https://www.iridologyassn.org/
IIPA 2021 Instructor of the Year: https://www.iridologyassn.org/
Certified Comprehensive Iridology Instructor Levels I, II, III: https://www.iridologyassn.org
Phones: (O) 530-878-1119 or (C) 530-368-0918
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