Vitamin D: “The Super Supplement” Vitamin D has been hailed a panacea in recent years by medical and fitness professionals as it encompasses a litany of health and performance boosting benefits. Traditionally held beliefs as a vitamin primarily related to bone health have evolved over the years. Yes, Vitamin D is intimately involved in producing and mineralizing bone, but it also wears many other hats as it simultaneously interacts with immune system, digestive system, thyroid glands, and metabolism.
D Defined Vitamin D consists of two forms: Ergocalciferol, commonly referred to as D2 and cholecalciferol, or known as D3. Ergocalciferol is derived from plant and fungal sources as its creation is triggered by ultraviolet irradiation. D2 is typically ingested when fruits, vegetables, and fungi, such as mushrooms, are consumed. Cholecalciferol is an endogenously occurring form of Vitamin D as it is synthesized from the skin’s exposure to ultraviolet B radiation from sunlight and from the consumption of animal products. Synthetic derivatives of D3 are often found in dietary supplements. Its classification and subsequent application, as well as dosage recommendations have drawn debate among professionals as its popularity continues to climb among health enthusiasts, lifters, and athletes.
Vitamin or Hormone? Vitamin D is more closely related to a hormone than a vitamin as it serves a precursor to calcitrol, the active vitamin D hormone resulting from metabolism in the liver and subsequent conversion by the kidneys, where it becomes 25-hydroxyvitamin D and interacts with a number of physiological systems. Too little vitamin D results impedes bone health, usually resulting in conditions such as rickets among children, and osteoporosis, osteopenia, and osteomalacia among adults. Additionally, inadequate consumption and/or malabsorption of vitamin D can lead to chronic fatigue, contribute to the formation of cancer cells, and decontrol metabolic functioning and cardiovascular health.
The Scoop on Vitamin D There is evidence to support its supplementation in the allaying of metabolic disease. Vitamin D prompts the release of insulin, arguably the body’s most powerful metabolic hormone, from the pancreas. Vitamin D profoundly impacts the body’s absorption and subsequent transport of calcium, a key mineral that plays a role in maintaining cellular fluid balance, facilitating muscular contraction, and osteoblastic functions such as mineralizing and repairing bone tissue. Reports have also surfaced which indicate that Vitamin D is capable of lowering blood pressure and boosting testosterone levels. Vitamin D is used to treat a wide range of ailments, including dermatological disorders and thyroid illness, and serves as an ancillary treatment for numerous cancers, although its effectiveness in doing so remains unproven. Sunlight is the best source of Vitamin D, as its UVB rays are absorbed by the skin to produce D3. However, for individuals who live further away from the equator, sun exposure will be lessened, especially during portions of the year that are colder or have more precipitation. These individuals run a greater risk of becoming deficient in vitamin D since they are outside less. The same holds true for aged individuals as their melanin, a component of the skin responsible for pigmentation, gradually loses the capability to absorb UVB rays. Fair skinned individuals who have less melanin may also be deficient in vitamin D as they are often inclined to avoid sun exposure. Darker skinned individuals are not immune from vitamin D deficiency, in spite of their skin having greater melanin content, if their exposure to sunlight is not consistent. Those in the northern hemisphere who live above 30 degrees latitude (a reference point for Americans is where Atlanta is located) have been found to have lower vitamin D levels. It should be noted that vitamin D levels have been reported to be the lowest during the early spring months among those living in the northern hemisphere. If unsure of your vitamin D levels, tests are available which measure circulating 25-hydroxyvitamin D content in the blood (a normal range of vitamin D spans from 30-74 ng/mL of blood). However, if you wish to avoid the expense and inconvenience of a test, foods rich in vitamin D, which include meats, poultry, beans, and fish (specifically, salmon, tuna, and mackerel) as well as fruits and vegetables, should be consumed with regularity if no dietary restrictions and/or allergies persist. Foods and drinks fortified with vitamin D may also be suggested for those wanting to boost vitamin D levels. While they differ structurally, a collection of research throughout the years suggests that D3 is superior to D2 in absorption due to enhanced bioavailability. While no universal guidelines exist pertaining to daily vitamin D consumption, amounts up to 600 IU per day recommended for adults up to age 70. It is advised that adults over the age of 70 consume up to 800 IU per day due to impaired UVB ray absorption. Greater amounts may be indicated for individuals wanting to prevent illnesses and in the treatment of diseases and infections. As it pertains to influencing hormones which impact athletic performance and body composition, greater doses of vitamin D have been suggested. Researchers have shown that consumption of 3,000 IU of Vitamin D per day elicited an average increase of 3 nmol following 12 months of supplementation. Vitamin D supplementation also encompasses neurocognitive benefits. According to Chris Policastro, Director of Wellness at Manhattan College, vitamin D supplementation may lead to improved academic performance. “Vitamin D has an anti-inflammatory effect which causes blood vessels to become dilated, allowing greater amounts of nutrient enriched blood to travel to brain cells.” Mr. Policastro cited recently emerging research which revealed a potential correlation between vitamin D supplementation and improvements in cortical perfusion. References
- Brouwer-Brolsma, E.M. & de Groot, L.C. (2014). Vitamin D and cognition in older adults: an update of recent findings. Current Opinion in Clinical Nutrition and Metabolic Care [Epub ahead of print]
- Pilz, S., Frisch, S., Koertke, H., et al. (2011). Effect of vitamin D supplementation on testosterone levels in men. Hormone and Metabolic Research, 43, 223-225.
Joe Giandonato, MS, CSCS, hails from a working class section of Philadelphia and is a formerly a manual laborer himself, working in warehouse and landscaping during college to pay his tuition. Joe is an avid Craigslist dater, “swag surfer”, and coupon clipper. He prefers deadlifting and finding money on the ground. He is an extremely private person and does not keep a blog, website, or push products, because he’s not an “expert”, instead he does what he loves – writing, training people, and deadlifting.