TLDR VDDR I and II are genetic disorders affecting vitamin D use, causing rickets, with VDDR I treatable by vitamin D supplements and VDDR II needing high doses and calcium.
Vitamin D-dependent rickets type I (VDDR I) and type II (VDDR II) were identified as hereditary defects in vitamin D metabolism. VDDR I was associated with a deficiency in renal 25-hydroxyvitamin D-1α-hydroxylase, leading to muscle weakness and rickets, which could be managed with normal doses of 1α-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3. VDDR II involved defects in the intracellular vitamin D receptor (VDR), characterized by severe rickets and alopecia due to mutations in the VDR gene. Treatment for VDDR II required large doses of vitamin D analogs and calcium, though the response varied.
47 citations,
October 1989 in “European Journal of Pediatrics” Two siblings stayed rickets-free for 14 years after stopping treatment.
50 citations,
October 1986 in “European journal of pediatrics” A boy with severe Vitamin D-resistant rickets did not respond to treatment and lacked a common symptom, suggesting a need for alternative treatments.
88 citations,
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.
43 citations,
December 2013 in “Seminars in Cell & Developmental Biology” Genetic mutations can cause hair growth disorders by affecting key genes and signaling pathways.
1 citations,
June 2021 in “International Journal of Dermatology” People with alopecia areata had lower vitamin D levels, but these levels didn't relate to many aspects of the condition.
6 citations,
August 1989 in “European journal of pediatrics” Child with rickets improved with a specific vitamin D therapy, but alopecia did not change.
1 citations,
January 2016 in “Journal of Nepal Paediatric Society” A child with rickets and hair loss might have a rare type of rickets that doesn't improve much with usual vitamin D and calcium treatment.
5 citations,
January 1970 in “Journal of Nepal Paediatric Society” Hair loss can be a key sign of a rare type of rickets when vitamin D treatment doesn't work and advanced tests aren't available.
