Ongoing treatment with pharmacologic doses of vitamin D, vitamin D metabolites or analogs Pregnant or lactating women Severe underlying diseases, such as an advanced malignant tumor, end-stage lung disease, etc. History of elevated serum calcium levels more than 10.6 mg/dl History of chronic hepatic, renal failure or patients with reduced kidney function, cancers, malabsorption syndrome, or granulomatous disorders such as Sarcoidosis or Tuberculosis Supplementation with over the counter formulations of vitamin D2 or vitamin D3 Use of tanning bed or artificial UV exposure within the last two weeks Consuming medication affecting bone metabolism (anti-convulsants, anti-tuberculosis medication, cimetidine, theophylline, and cholestyramine) Following special diets such as vegetarian diet or consuming fortified products regularly A history of an adverse reaction to orally administered vitamin D, vitamin D metabolites or analogs Inability to give informed consent

Ongoing treatment with pharmacologic doses of vitamin D, vitamin D metabolites or analogs Pregnant or lactating women Severe underlying diseases, such as an advanced malignant tumor, end-stage lung disease, etc. History of elevated serum calcium levels more than 10.6 mg/dl History of chronic hepatic, renal failure or patients with reduced kidney function, cancers, malabsorption syndrome, or granulomatous disorders such as Sarcoidosis or Tuberculosis Supplementation with over the counter formulations of vitamin D2 or vitamin D3 Use of tanning bed or artificial UV exposure within the last two weeks Consuming medication affecting bone metabolism (anti-convulsants, anti-tuberculosis medication, cimetidine, theophylline, and cholestyramine) Following special diets such as vegetarian diet or consuming fortified products regularly A history of an adverse reaction to orally administered vitamin D, vitamin D metabolites or analogs Inability to give informed consent