Vitamin D: Recent research uncovers new benefits

As much of the world experiences a record-breaking heat wave, this Spotlight turns its attention to vitamin D, the so-called sunshine vitamin. Here, we inspect the latest research.
Tropical sun
The “sunshine vitamin” has a range of surprising benefits.
Vitamin D is a hot topic currently, with a raft of studies proclaiming its benefits for a variety of serious conditions.

Conversely, other recent studies have been more cautious, questioning its perceived usefulness for treating some illnesses.

Vitamin D is a nutrient that is synthesized in our skin when it is exposed to sunlight, and it is also present in some foods.

Sunlight is the best source of vitamin D, but in the winter months, the National Institutes of Health (NIH) recommend topping up vitamin D levels by eating vitamin D-containing foods each day. These include oily fish, fortified milk, beef liver, egg yolks, mushrooms, and fortified breakfast cereals.

What does vitamin D do?
Scientists know that vitamin D is essential for many aspects of maintaining good health and that deficiency is linked with problems for both physical and mental health.

Perhaps most notably, vitamin D helps to regulate the levels of calcium in our bodies, strengthening our bones and preventing bone-weakening conditions, such as osteoporosis.

Increasingly though, studies are also suggesting that vitamin D might have protective benefits against heart failure, diabetes, cancer, respiratory tract infections, autoimmune disease, and even hair loss.

A surprisingly large number of people have insufficient levels of vitamin D. For instance, according to one study, more than 40 percent of adults in the United States are deficient. Because of its prevalence, it is important to determine what the public health implications of this epidemic might be.

Symptoms of vitamin D deficiency can vary between individuals, but they typically include pain in the joints, muscles, or bones; fatigue; breathing problems; and low mood or seasonal affective disorder (SAD).

Below, we run through a number of intriguing recent studies that investigate associations between vitamin D and an assortment of illnesses.

Vitamin D and heart failure
Several studies have suggested that vitamin D could offer protective benefits against cardiovascular illness, but scientists have yet to pinpoint what mechanisms are driving this association.

Recently, though, Medical News Today reported on a study that used a mouse model to investigate how a type of vitamin D, called 1,25-dihydroxyvitamin D3, affects heart cells. In particular, the researchers looked at the cells responsible for developing scar tissue following a heart attack, called cardiac colony-forming unit fibroblasts (cCFU-Fs).

cCFU-Fs are an important area of study because, when heart tissue is scarred, the heart has a harder time pumping blood, which can lead to heart failure.

The researchers behind the study found that vitamin D inhibited the action of cCFU-Fs, which prevented scar tissue from building around the hearts of the mice in the study, potentially preventing blockages in the cardiovascular system.

“With further study,” wrote the authors, “vitamin D could prove to be an exciting, low-cost addition to current treatments, and we hope to progress these findings into clinical trials for humans.”

Vitamin D and cancer
Breast cancer and bowel cancer have both been linked with cases of vitamin D deficiency in recent studies. One of these analyzed data from two randomized clinical trials and a prospective cohort study.

The researchers found that high levels of vitamin D were inversely associated with risk of breast cancer among women who were cancer-free at baseline.

Pink ribbon blue background
Studies suggest that vitamin D impacts breast cancer risk.
According to the study results, the higher the levels of vitamin D, the lower the risk of breast cancer.

This relationship remained significant even after the results were adjusted for confounding factors, such as age, body mass index (BMI), intake of calcium supplements, and smoking habits.