Vitamin D’s effects on the human body are staggering. It is involved in muscular and skeletal health, insulin and blood sugar levels, the immune system, and the metabolism of phosphorus and calcium. Vitamin D’s reputation as being the vitamin responsible for healthy bones and teeth lies mainly in its role in regulating calcium and phosphorus levels: it keeps levels of parathyroid hormone in the bloodstream at ideal concentrations. Too much parathyroid hormone leaches calcium from the bones and keeps it at unhealthy levels in the bloodstream. Vitamin D’s role in proper immune responses is so vital that there are actually vitamin D receptors on the macrophages of the immune system.
Vitamin D Deficiency
People can synthesize vitamin D just from being outside for fifteen minutes or more, whether or not it is a particularly ‘sunny’ day. The production of vitamin D is unique amongst all of our important nutrients. Humans have a form of cholesterol in our skin cells called 7-dehydrocholesterol, which is one of the basic building blocks of vitamin D3. Ultraviolet hits the skin, and reacts with 7-dehydrocholesterol to form cholecalciferol, or vitamin D3. Cholecalciferoland other types of vitamin D3 represent the best form of the vitamin, in terms of its use by the body.
Pregnant women, aged people, people with kidney or parathyroid gland problems, people who habitually limit their sun exposure, and those with certain genetic predispositions are at an increased risk of vitamin D deficiency. Vitamin D is a fat-soluble vitamin, meaning the body stores it in fat tissue, and toxicity is a greater risk than with water-soluble vitamins. However, prolonged vitamin D deficiency is both more common and more potentially problematic than prolonged vitamin
Vitamin D toxicity symptoms include high blood pressure, gastrointestinal problems, and kidney dysfunction. The symptoms of vitamin D deficiency include musculoskeletal problems, lowered immune response, cognitive problems, and depression. In children, prolonged deficiency can lead to growth problems and asthma. For older people, vitamin D levels seem to play an important role in the prevention of many serious illnesses, including cancer, osteoporosis, high blood pressure, heart problems, stroke, Type 2 diabetes, infectious disease susceptibility, autoimmune disorders, and cognitive decline. Adults aged 19-70 should get fifteen micrograms, or 600 IU, of vitamin D per day, expanding to 800 IU as 70-year-olds.
The single best source of dietary vitamin D is salmon. Cow’s milk and sardines are very good sources, and goat’s milk, shiitake mushrooms, and whole eggs are good sources. Anyone relying on eggs as a vitamin D source should eat the yolks, too. Wild salmon and organically farmed salmon generally have exhibited higher vitamin D levels than standard farmed salmon.