Most people have heard that vitamin D is an “essential” nutrient for the human body. Vitamin D is necessary for the body to absorb calcium and promote bone growth. Vitamin D deficiency has been linked to heart disease, depression, weight gain, and has proven helpful in treating or preventing autism, autoimmune disease, various cancers, chronic pain, diabetes, high blood pressure, neuromuscular diseases, and osteoporosis.
And a recent study shows a strong correlation between higher levels of vitamin D and a marked decrease in the prevalence of breast cancer.
Now you know why your mom told you to drink your milk.
Was up for debate
The merits of vitamin D and cancer prevention have been an area of contention in the medical world. Past studies have shown a lower overall risk of cancer with higher levels of vitamin D. But other studies have seemed to show no correlation.
But the debate is tilting toward the benefits of vitamin D. Low blood levels of vitamin D have been associated with a raised risk of bladder cancer and bowel cancer in two different studies. Previous research also suggested a link between high vitamin D levels and higher survival rates for breast cancer.
Two new studies add more weight for vitamin D.
A group of researchers from the University of California, San Diego School of Medicine, in collaboration with researchers from Creighton University in Nebraska and the Medical University of South Carolina, analyzed the data of two randomized clinical trials with a total of 3,325 participants, and another with 1,713 participants. All of the participants in these studies were women with an average age of 63. All were cancer-free at baseline. The data used was collected from 2002-2017, and the participants’ health was followed for a mean period of four years.
The specific focus was to look for associations between the risk of developing breast cancer and blood serum concentrations of 25-hydroxyvitamin D (25(OH)D), a prominent vitamin D biomarker in the study participants.
During the period of the three studies, a total of 77 new cases of breast cancer were reported. The research notes that the rate of breast cancers was 512 cases per 100,000 person years in the pooled numbers.
The analysis of the three studies showed that people with higher blood concentrations of the vitamin D biomarker had a significantly lower risk of breast cancer.
Dr. Cedric F. Garland, one of the authors of the new study, noted, “We found that participants with blood levels of 25(OH)D that were above 60 nanograms per milliliter had one-fifth the risk of breast cancer compared to those with less than 20 nanograms per milliliter.”
Garland and the research team estimated that the minimum healthy level of 25(OH)D in blood should be about 60 nanograms per milliliter, which is much high than the 20 nanograms per milliliter concentration currently recommended by the National Institutes of Health.
These finding held true even after the research team adjusted the analysis results for potential influencing factors, such as the participants’ age, body mass index, smoking habits, and the consumption of calcium supplements.
“Increasing vitamin D blood levels substantially above 20 nanograms per milliliter appears to be important for the prevention of breast cancer,” first study author Sharon McDonnell writes.
The new research did note that the pool of participants in the three studies used was limited to postmenopausal breast cancer, so more research is needed on if vitamin D levels might also help prevent premenopausal breast cancer.
“Nonetheless,” Garland concludes, “this paper reports the strongest association yet between serum vitamin D and reduction in risk of breast cancer.”
More vitamin D
OK, so it looks like more vitamin D is good for your body in many areas. So where do you get the stuff? Your body creates vitamin D on its own after you’ve been out in the sun. So, that’s an easy source.
Everyone knows you get vitamin D from milk/dairy. So, drink milk, eat yogurt, munch on cheese, and live it up with egg nog during the holidays. Vitamin D is also big in both fresh and canned fish. You find it in beef and beef liver. Shiitake mushrooms have lots of vitamin D, as does tofu. Oatmeal and orange juice are usually fortified with vitamin D. So is breakfast cereal, which is otherwise pretty much nutritionless, except for the vitamins sprayed onto it.