Subjects

ELDERS (>65 years), (often underestimated in the deficiency of males)

OBESE

WITH LIMITED EXPOSURE TO THE SUN

WITH DARK SKIN (e.g. African Americans)

WITH FATS malabsorption (e.g. Inflammatory bowel disease, celiac disease, liver disease, gastrointestinal bypass, etc.)

WITH SEVERE THINNESS and/or food intake disorders (ex. Anorexia)

WITH INCREASE OF VD REQUIREMENTS (pregnancy, lactation)

IN TREATMENT WITH DRUGS THAT INTERFERE WITH ITS METABOLISM (anticonvulsants, long-term glucocorticoids, antifungals, HIV + drugs, immunosuppressive drugs)

WITH DISEASES THAT INCREASE ITS METABOLISM (lymphomas, granulomatosis, primary hyperparathyroidism)

WITH EXTENDED DERMATOLOGICAL DISEASES (e.g. psoriasis, atopic dermatitis, vitiligo)

WITH DECREASED SYNTHESIS OF ACTIVE VD (chronic renal failure, liver failure)

WITH OSTEOPOROSIS OR NOTES OF OSTEOMALACIA, or with frequent spontaneous fractures

WITH FAMILY HISTORY OF BONE FRAGILITY FRACTURE