TLDR  Intravenous and oral calcium effectively treated vitamin D dependent rickets type II, improving growth and bone health.   
  The study assessed the effectiveness of intravenous high-dose calcium infusions followed by high-dose oral calcium in treating vitamin D dependent rickets type II (VDDRII) in two siblings. The treatment normalized calcium and phosphate levels within 3-5 days and alkaline phosphatase and PTH levels within 15-20 months, with radiological healing observed in 42 days. The elder sister received daily infusions for 3-5 months, and the younger brother for 2 months, both followed by weekly infusions and maintenance on oral calcium. The treatment led to complete biochemical and radiological healing, improved height, and no evidence of nephrocalcinosis or kidney function deterioration. Early treatment was crucial for better growth and prevention of bone deformities, and it may also improve alopecia, though the mechanism requires further investigation.
                     110 citations
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  November 1984   in “The American Journal of Medicine”    A genetic defect in vitamin D receptors causes severe rickets and hair loss in children, but some heal as they age.  
               88 citations
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  October 1983   in “The Journal of clinical endocrinology and metabolism/Journal of clinical endocrinology & metabolism”    Patients with this syndrome can have different responses and worsening resistance to treatment over time.  
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  April 1981   in “Clinical endocrinology”
           82 citations
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  April 1981   in “Clinical endocrinology”    A girl with rickets and hair loss was found to have a rare condition where her body didn't respond to vitamin D treatment.  
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  May 1979   in “The journal of pediatrics/The Journal of pediatrics”    Two sisters with rickets and hair loss had a genetic issue with vitamin D processing, and only improved when given phosphorus supplements.  
    
  
        
                 717 citations
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  June 2010   in “Nature”    Alopecia areata involves both innate and adaptive immunity, with specific genes linked to the disease.  
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  August 2014   in “Nature medicine”    Alopecia areata can be reversed by JAK inhibitors, promoting hair regrowth.  
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  October 1998   in “Endocrinology”    Diet can prevent bone issues but not hair loss in mice lacking vitamin D receptors.  
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  April 2012   in “The New England Journal of Medicine”
           421 citations
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  April 2012   in “The New England Journal of Medicine”    Alopecia Areata is an autoimmune condition causing hair loss with no cure and treatments that often don't work well.  
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  January 2010   in “Journal of The American Academy of Dermatology”
           391 citations
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  January 2010   in “Journal of The American Academy of Dermatology”    Half of people with Alopecia Areata may see hair regrowth within a year without treatment, but recovery is unpredictable.  
      295 citations
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  January 2006   in “Journal of the American Academy of Dermatology”
           295 citations
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  January 2006   in “Journal of the American Academy of Dermatology”    Alopecia areata, a common autoimmune hair loss condition, often runs in families.