Vitamin D, also known as the sunshine vitamin, has enjoyed something of a celebrity status, receiving praise for a multitude of health benefits. Yet, in the complex web of biological processes that govern our health, few players ever work in isolation. New evidence shifts the focus onto magnesium, implicating it in playing a central role in determining how much vitamin D our bodies can make.
In a study that features in the December issue of The American Journal of Clinical Nutrition, a research team from Vanderbilt University Medical Center in Nashville, TN concludes that optimal levels of magnesium may play an important role in the vitamin D status of an individual.
Dr. Qi Dai, a professor of medicine at Vanderbilt University Medical Center and the lead study author, previously reported on the relationship between magnesium intake and vitamin D levels in over 12,000 individuals taking part in the National Health and Nutrition Examination Survey (NHANES) 2001–2006 study.
Here, Dr. Dai and team found that individuals with high levels of magnesium intake, whether from dietary sources or taking supplements, were less likely to have low levels of vitamin D. Importantly, the researchers also found a possible association between magnesium intake and a reduction in mortality, particularly when they looked at mortality due to cardiovascular disease and bowel cancer.
So, how does magnesium affect vitamin D biology in the body? It is a cofactor in the synthesis of vitamin D from both exposure to sunlight and dietary sources. "Magnesium deficiency shuts down the vitamin D synthesis and metabolism pathway," Dr. Dai explains.
While the data from the NHANES study indicated a link between magnesium, vitamin D, and mortality, the team did not design the study to show whether giving an individual extra magnesium would change their vitamin D levels. To look at the link between magnesium supplementation and vitamin D levels in more detail, Dr. Dai and colleagues worked with a subset of 180 individuals taking part in the Personalized Prevention of Colorectal Cancer Trial, which enrolled a total of 250 individuals.
Treatment with a magnesium supplement led to an increase in vitamin D levels in people who had low levels initially, but it reduced levels of the sunshine vitamin in those with high levels. This is important because there is an association between too much vitamin D and excess calcium in the blood (hypercalcemia), which can cause serious health complications. On the other hand, researchers have linked low levels of vitamin D with a variety of symptoms, and Dr. Dai is particularly interested in its role in bowel cancer.
I frequently recommend magnesium supplementation and vitamin D is one of my top five most commonly recommended supplements. Magnesium is a cofactor in the sulfur amino acid pathway and the Krebs’s citric acid cycle, both crucial to detoxification and metabolism in the human body.
Magnesium has a sedative effect on the nervous system. Most commonly I use it, in combination with other supplements, to treat tachycardia and Afib.
You can titrate magnesium to maximum dosage. Start with 100mg and increase by 100mg per day until the stool becomes loose. Back off by 100mg and that is your loading dose. You may have to reduce it further as you resolve any deficiency, but the loose stool will guide you. Additionally, you may need to increase your magnesium intake in times of high stress.