Jerry Levine, M.D.

While we have always associated vitamin D with bone Calcium and bone metabolism, there is enough information available now showing an association with Vitamin D and solid tumor cancer risks and heart disease. There have not been any published prospective or interventional studies; however, there have been recent articles associating a 50% reduction of the incidence of breast cancer with 25hydroxyVitamin D levels greater than 34ng/ml. There is also documented data associating Vitamin D levels with colorectal cancer, ovarian, prostate, and nonsmall cell lung cancer. Low circulating levels of 25-hydroxyvitamin D can be correlated with increased cardiovascular and hypertension risk. The evidence goes on to include association with multiple sclerosis, periodontal disease, and immunity/infection.

Vitamin D sources are dietary (cheese, milk, eggs) and sunlight production in the skin producing Vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) both are Fat soluble and can accumulate in excess. Vitamin D is hydroxylated to 25-hydroxyVit D in the liver, and subsequently is converted to the active form and water soluble form in the kidney 1-25 hydroxyVitamin D (calcitiol). Actions include Cell differentiation, immune function, calcium uptake in cardiac myocytes (participating in contractility and inhibiting atrial naturetic peptide), also calcium uptake in skeletal muscle, pancreatic islets, and pituitary.

25 Hydroxy Vitamin D is the major circulating form of vitamin D and is what should be measured for clinical Vitamin D status. It would be rare that 1-25 hydroxy VitD levels would be low, except in renal failure. Vitamin D deficiency is more common in infants who are exclusively breast fed, adults with increased skin pigmentation, always wearing sun blocker, confined to the indoors, GI disorders of malabsorption, and post bariatric surgery. Individuals using chronic anticonvulsant therapy (dilatin) are also susceptible. Signs and symptoms of deficiency include muscle aches and weakness; Bone osteomalacia, fractures, and bone pain; and joint aches and stiffness. Plasma 25(OH)D levels: <20ng/dl increases secondary hyperparathyroidism, levels 30-40 are optimal, and upper accept level is about 100 mg/dl.

Repletion should be Ergocalciferol (Vit D2) 50,000 units 1-2x weekly for 4-6 weeks. Maintenance would be Over the Counter Cholecalciferol (vit D3) 800-2000 Units daily, or Ergocalciferol 50,000Units monthly. Monitor 25 OHVitD, PTH, and calcium levels.

In summary epidemiological studies demonstrate low 25(OH)D levels to be associated with osteomalacia, higher cancer risks, and other disease risks. Check 25-(OH) Vit D levels on your patients. Prospective studies are still required to if optimizing 25-OH VitD is key to reducing and preventing Cancer, Diabetes, Cardiovascular disease, and premature death.

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