1. ongoing treatment with pharmacologic doses of vitamin d, vitamin d metabolites or analogues 2. pregnant or lactating women; 3. severe underlying diseases, such as advanced malignant tumors, endstage lung disease, etc. 4. history of elevated serum calcium \>10.6 mg/dl; that is corrected for albumin concentration or subjects with a history of hypercalciuria and kidney stones. 5. chronic hepatic dysfunction, chronic kidney disease or intestinal malabsorption syndromes including inflammatory bowel disease. 6. supplementation with over the counter formulations of vitamin d2 or vitamin d3 7. use of tanning bed or artificial uv exposure within the last two weeks. 8. consuming medication affecting vitamin d metabolism or absorption (anticonvulsants, anti-tuberculosis medication glucocorticoids, hiv medications and cholestyramine). 9. subjects with a history of an adverse reaction to orally administered vitamin d, vitamin d metabolites or analogues. 10. subjects with a history of conditions that can lead to high serum calcium levels such as sarcoidosis, tuberculosis and some lymphomas associated with activated macrophages which increase the production of 1,25(oh)2d. 11. inability to give informed consent

1. ongoing treatment with pharmacologic doses of vitamin d, vitamin d metabolites or analogues 2. pregnant or lactating women; 3. severe underlying diseases, such as advanced malignant tumors, endstage lung disease, etc. 4. history of elevated serum calcium \>10.6 mg/dl; that is corrected for albumin concentration or subjects with a history of hypercalciuria and kidney stones. 5. chronic hepatic dysfunction, chronic kidney disease or intestinal malabsorption syndromes including inflammatory bowel disease. 6. supplementation with over the counter formulations of vitamin d2 or vitamin d3 7. use of tanning bed or artificial uv exposure within the last two weeks. 8. consuming medication affecting vitamin d metabolism or absorption (anticonvulsants, anti-tuberculosis medication glucocorticoids, hiv medications and cholestyramine). 9. subjects with a history of an adverse reaction to orally administered vitamin d, vitamin d metabolites or analogues. 10. subjects with a history of conditions that can lead to high serum calcium levels such as sarcoidosis, tuberculosis and some lymphomas associated with activated macrophages which increase the production of 1,25(oh)2d. 11. inability to give informed consent

ongoing treatment with pharmacologic doses of vitamin d, vitamin d metabolites or analogues pregnant or lactating women; severe underlying diseases, such as advanced malignant tumors, endstage lung disease, etc. history of elevated serum calcium >10.6 mg/dl; that is corrected for albumin concentration or subjects with a history of hypercalciuria and kidney stones. chronic hepatic dysfunction, chronic kidney disease or intestinal malabsorption syndromes including inflammatory bowel disease. 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 vitamin d metabolism or absorption (anticonvulsants, anti-tuberculosis medication glucocorticoids, hiv medications and cholestyramine). subjects with a history of an adverse reaction to orally administered vitamin d, vitamin d metabolites or analogues. subjects with a history of conditions that can lead to high serum calcium levels such as sarcoidosis, tuberculosis and some lymphomas associated with activated macrophages which increase the production of 1,25(oh)2d. inability to give informed consent

ongoing treatment with pharmacologic doses of vitamin d, vitamin d metabolites or analogues pregnant or lactating women; severe underlying diseases, such as advanced malignant tumors, endstage lung disease, etc. history of elevated serum calcium >10.6 mg/dl; that is corrected for albumin concentration or subjects with a history of hypercalciuria and kidney stones. chronic hepatic dysfunction, chronic kidney disease or intestinal malabsorption syndromes including inflammatory bowel disease. 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 vitamin d metabolism or absorption (anticonvulsants, anti-tuberculosis medication glucocorticoids, hiv medications and cholestyramine). subjects with a history of an adverse reaction to orally administered vitamin d, vitamin d metabolites or analogues. subjects with a history of conditions that can lead to high serum calcium levels such as sarcoidosis, tuberculosis and some lymphomas associated with activated macrophages which increase the production of 1,25(oh)2d. inability to give informed consent

1. ongoing treatment with pharmacologic doses of vitamin d, vitamin d metabolites or analogues 2. pregnant or lactating women; 3. severe underlying diseases, such as advanced malignant tumors, endstage lung disease, etc. 4. history of elevated serum calcium >10.6 mg/dl; that is corrected for albumin concentration or subjects with a history of hypercalciuria and kidney stones. 5. chronic hepatic dysfunction, chronic kidney disease or intestinal malabsorption syndromes including inflammatory bowel disease. 6. supplementation with over the counter formulations of vitamin d2 or vitamin d3 7. use of tanning bed or artificial uv exposure within the last two weeks. 8. consuming medication affecting vitamin d metabolism or absorption (anticonvulsants, anti-tuberculosis medication glucocorticoids, hiv medications and cholestyramine). 9. subjects with a history of an adverse reaction to orally administered vitamin d, vitamin d metabolites or analogues. 10. subjects with a history of conditions that can lead to high serum calcium levels such as sarcoidosis, tuberculosis and some lymphomas associated with activated macrophages which increase the production of 1,25(oh)2d. 11. inability to give informed consent

1. ongoing treatment with pharmacologic doses of vitamin d, vitamin d metabolites or analogues 2. pregnant or lactating women; 3. severe underlying diseases, such as advanced malignant tumors, endstage lung disease, etc. 4. history of elevated serum calcium >10.6 mg/dl; that is corrected for albumin concentration or subjects with a history of hypercalciuria and kidney stones. 5. chronic hepatic dysfunction, chronic kidney disease or intestinal malabsorption syndromes including inflammatory bowel disease. 6. supplementation with over the counter formulations of vitamin d2 or vitamin d3 7. use of tanning bed or artificial uv exposure within the last two weeks. 8. consuming medication affecting vitamin d metabolism or absorption (anticonvulsants, anti-tuberculosis medication glucocorticoids, hiv medications and cholestyramine). 9. subjects with a history of an adverse reaction to orally administered vitamin d, vitamin d metabolites or analogues. 10. subjects with a history of conditions that can lead to high serum calcium levels such as sarcoidosis, tuberculosis and some lymphomas associated with activated macrophages which increase the production of 1,25(oh)2d. 11. inability to give informed consent