The Deal with Vitamin D
Vitamin D, also known as calciferol, is a fat-soluble vitamin (stored in the liver and fatty tissue). We obtain Vitamin D from food, or from skin exposure to UVB sunlight; and, it is processed by the liver and kidneys to its active form (1,25-hydroxycholecalciferol).
The main function of Vitamin D is to regulate our blood levels of calcium and phosphorous. It helps to “mineralize” (add calcium crystals for strength) bone, so deficiency may lead to bone softening or thinning. Supplementation will prevent/treat osteomalacia in adults and rickets in children. Vitamin D may help to prevent high blood pressure, limit heart disease, enhance immune function, and may even protect against some forms of cancer, particularly pancreatic and colon. It is important to note that appropriate calcium and magnesium levels are necessary for Vitamin D therapy, and should be supplemented if needed.
Vitamin toxicity (also known as hypervitaminosis, vitamin poisoning) refers to symptoms or side effects from inappropriately high levels in the blood. Vitamins that may cause toxicity are those that are fat-soluble (Vitamins A, D, E, and K). Toxicity is extremely rare, especially with doses less than 10,000 IU daily, and cannot occur from sun exposure. The earliest signs of Vitamin D toxicity are usually from elevated calcium levels and include loss of appetite, nausea, vomiting, weakness, confusion, or even kidney stones. If you are taking any of the fat-soluble vitamins on a regular basis, please be sure to have a clinician monitor your blood levels routinely!