- Recent research has investigated the potential health benefits of vitamin D, and the role it may play in protecting against certain health conditions.
- One study found that vitamin D may have anticancer effects, which could help reduce colorectal cancer risk.
- Another piece of research suggests that vitamin D may contribute to longevity and slow aging.
- A third recent study also indicates that vitamin D might drastically reduce the risk of experiencing a second heart attack.
Vitamin D is a hormone
It is naturally present in some foods, added to others, and available as a dietary supplement. The skin also produces vitamin D in response to sun exposure.
Still, vitamin D deficiency is one of the most common nutritional deficiencies worldwide, with nearly
The recommended daily amount for most people is around 15 micrograms (mcg), or 2,000 international units (IU). However, it is important to note that
Medical News Today looks at three recent studies to examine the possible role vitamin D may have in supporting Health and boosting longevity.
A recent literature review of 50 studies and more than 1 million participants suggest that vitamin D may help decrease the risk of colorectal cancer and also improve survival for the condition.
Published in Nutrients in April 2025, the review found that higher serum vitamin D levels were associated with a reduced risk of colorectal cancer. Additionally, among those with colorectal cancer, higher vitamin D levels were linked to improved survival and reduced mortality.
The authors of the review suggested that vitamin D helps the immune system and may assist with decreasing inflammation.
Vitamin D may also possess specific anticancer properties, such as supporting programmed cell death and stopping uncontrolled cell growth. The authors added that vitamin D may be a useful adjunctive option alongside other cancer treatments.
However, despite these promosing associations, the researchers noted that more research is still necessary, particularly large-scale, randomized clinical trials.
While some research noted that both dietary vitamin D and vitamin D supplements have beneficial effects on colorectal cancer, other studies did not find a significant relationship between vitamin D and colorectal cancer.
Some studies highlighted that results may differ due to factors such as body mass index (BMI), sex, and nutritional status. It may be helpful for further research to explore components like how people’s genetics, lifestyle choices, and use of other treatments play a role in vitamin D’s effects on cancer.
Wael Harb, MD, a board-certified hematologist and medical oncologist at MemorialCare Cancer Institute at Orange Coast and Saddleback Medical Centers in Orange County, CA, who was not involved in the study, commented to MNT that:
“For patients with [colorectal cancer], ensuring adequate vitamin D levels may help support immune surveillance and potentially improve outcomes when used alongside standard therapies. Importantly, this review highlights the need for personalized approaches, as individual vitamin D requirements can vary based on genetics, baseline levels, and comorbidities.”
A study published in The American Journal of Clinical Nutrition in July 2025 suggested that vitamin D supplemention could preseve the length of telomeres in white blood cells, which may help to slow down biological aging.
For this study, researchers used data from the large-scale VITAL trial in the U.S. This trial included a representative sample of adults receiving vitamin D3 supplements, omega-3 fatty acid supplements, or both for around 5 years.
Participants were randomized, with half receiving 2,000 IU, or 50 mcg, of vitamin D daily, and the remaining receiving a placebo.
The findings indicated that in those receiving vitamin D3, telomere shortening in
Further analysis suggested that the effect of vitamin D was more evident in participants who did not have obesity, those not taking cholesterol-lowering medications, and in participants of different ethnicities. Omega-3 fatty acids supplementation appeared to have no significant impact on telomere length.
Yoshua Quinones, MD, a board-certified internist with Medical Offices of Manhattan and contributor to LabFinder, who was not involved in the study, explained that:
“As we know already, vitamin D supports bone, immune system and reduces inflammation, but this study is linked directly with telomere preservation which ties into aging and disease prevention. This [study] gives more of a general idea that vitamin D3 could do more than just helping your bones but actually slowing down the cellular age, impressive!”
However, the researchers acknowledge that the analysis was a post-hoc examination of the VITAL trial, which was not originally designed to look at the effects of supplements on leukocyte telomere length.
Additionally, most participants were white and older adults, so it may not be possible to generalize the findings to other groups.
Previous research has suggested a link between low levels of vitamin D and poor cardiovascular health, and a newer study now indicates that vitamin D3 supplementation may help to drastically reduce the risk of having a second heart attack.
Intermountain Health researchers presented their study at the
The TARGET-D trial involved 630 participants, most of which were males with an average age of 63, who enrolled within a month of having a heart attack. The researchers randomly selected the control group and who would receive targeted vitamin D3 treatment.
At enrollment, 87% of participants had low vitamin D levels and the average vitamin D level was 27 nanograms/milliliter (ng/ml).
The researchers tailored vitamin D3 supplementation by measuring blood vitamin D levels and adjusting the dose so that individuals reached a target serum level of approximately 40 ng/ml.
The researchers monitored vitamin D3 levels throughout the trial and would adjust doses to maintain the target level. They also kept track of major cardiovascular events throughout the trial.
Although there was no significant difference between groups in overall cardiac events, the rate of follow-up heart attacks was 3.8% in the vitamin D3 treatment group compared to 7.9% in the control group.
Overall, while the results suggest that targeted vitamin D3 supplementation may not reduce all major cardiac outcomes, it did cut the risk of repeat heart attacks by more than half.
Cheng-Han Chen, MD, a board-certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center, who was not involved in this study, explained that while past research has linked higher blood levels of vitamin D with lower heart disease rates, “it mostly appears that the relationship between vitamin D3 and heart health is that of correlation rather than that of causation.”
He noted that vitamin D3 may still offer some cardiovascular benefits, such as “decreasing inflammation and lowering blood pressure.”
However, he cautioned that the evidence remains mixed. He added that if larger studies confirm the recent finding that targeted vitamin D3 treatment could reduce the risk of recurrent heart attacks, “it would be quite significant.”
