December 17, 2019

Vitamin D continues to be in the news, and with good reason. Recent studies suggest a potential benefit for the vitamin against Hodgkin lymphoma and cancer mortality and a protective effect in an area of the brain involved with memory and learning.

A case-control study evaluated the effects of vitamin D levels in 351 participants in the German Hodgkin Study Group clinical trials, which compared the effects of chemotherapy alone to chemotherapy with radiation in Hodgkin lymphoma patients. Serum 25-hydroxyvitamin D was measured prior to the patients’ treatments and patients were followed for a median of 13 years. For the current investigation, each participant with relapsed or progressive disease was compared to two non-relapsed control participants.

Fifty percent of the group were categorized as having deficient vitamin D levels of less than 12 nanograms per milliliter (ng/mL). Among patients who were relapsed or resistant to treatment, a significantly higher portion had deficient vitamin D levels in comparison with the non-relapsed subjects. Participants with vitamin D deficiency had lower progression-free survival and overall survival at five and ten years compared to those who were not deficient. Experimentation in cultured cells showed antiproliferative effects for vitamin D in combination with chemotherapy, and in mice, supplementation with the vitamin reduced the rate of tumor growth when combined with chemotherapy compared to either treatment alone.

A meta-analysis of ten randomized trials published on November 29, 2019 in Bioscience Reports found that the risk of dying from cancer was 13% lower among participants who received vitamin D supplements compared to those who received a placebo. The trials included a total of 81,362 participants and evaluated the effects of vitamin D supplementation on cancer incidence and cancer mortality during periods that ranged from 48 to 113 months. The authors announced that “This is thus far the largest meta-analysis of randomized controlled trials that has assessed the association of vitamin D supplement with cancer incidence and mortality.”

And in a study that included 215 older men and women, published on November 13, 2019 in Current Alzheimer Research, measurement of vitamin D levels that were classified as insufficient at 20 ng/mL were associated with a thinner cingulate cortex, which is an area of the brain related to cognitive functions affected by vitamin D. The cingulate cortex is part of the limbic system, which is involved in emotion, learning and memory.  Assessment of three regions of the cingulate cortex via magnetic resonance imaging (MRI) found significant correlations between serum 25-hycrosyvitamin D levels and thickness of all regions examined.

These investigations are among the more notable of the ongoing research demonstrating the benefits of vitamin D sufficiency in many areas of health. We look forward to the revelation of yet unknown areas that may benefit from improved vitamin D status.