The Vitamin D Society wants to make the public aware of a new review published by the Mayo Clinic, which highlights the global health benefits and disease prevention opportunities available through the achievement of optimal levels of vitamin D. The study found that vitamin D deficiency is a common underdiagnosed condition throughout the world. Recent evidence from hundreds of studies suggests that vitamin D is important for reducing the risk of type 1 diabetes mellitus, cardiovascular disease, certain cancers, cognitive decline, depression, pregnancy complications, autoimmunity, allergy and even frailty. The best method to determine if you are deficient in vitamin D is through a 25(OH)D blood test. Vitamin D deficiency during pregnancy may influence fetal “imprinting” that may affect chronic disease susceptibility soon after birth as well as later in life. An effective strategy to prevent vitamin D deficiency and insufficiency is to obtain some sensible sun exposure (dminder.info is a free app that provides guidance for sensible sun exposure), ingest foods that contain vitamin D, and take a vitamin D supplement(1).
“The bottom line is that vitamin D has many health benefits and this could be in part due to its effects on both genomic activity and epigenetics,” said Michael F. Holick, PhD, MD, professor of medicine, physiology and biophysics at BUSM and leading vitamin D expert who is a co-author of this study. “There are an estimated 2,000 genes that are directly or indirectly regulated by vitamin D through vitamin D receptors located in most tissues and cells in the body. Vitamin D can directly influence the expression and activity of a wide variety of genes which are important for controlling a wide variety of biologic processes including controlling cellular growth to prevent malignancy.”
Humans obtain a considerable amount of their vitamin D requirement from sun exposure, Dr. Holick reports, there is no evidence that sensible sun exposure, as our forefathers likely experienced, increases risk of nonmelanoma skin cancer. An adult in a bathing suit exposed to 1 minimal erythemal dose (slight pinkness to the skin 24 hours after exposure) is the equivalent to taking approximately 20,000 IU of vitamin D orally.
The Endocrine Society has suggested that the maintenance of a 25(OH)D level of 40 to 60 ng/ml or 100-150 nmol/L is ideal and that levels up to 100 ng/ml or 250 nmol/L are safe(2). This may be achieved through a recommended intake of 1500-2000 IU worth of vitamin D per day with a safe upper limit (UL) of 10,000 IU.
“Only 10% of Canadians achieve the optimal vitamin D level of 100 nmol/L (40 ng/ml USA),” said Perry Holman, executive director for the Vitamin D Society. “We need to work harder to communicate the disease prevention research to the public and show them how important maintaining optimal vitamin D levels year around are for your health.”
The review concluded that there is no downside to increasing the vitamin D status of children and adults throughout the world. There is potentially a great upside in terms of improving overall health and well-being.