Hi Susan,

From what I remember from looking this up in the past, other nutritional deficiencies associated with hair loss in addition to vitamin B12 include iron, zinc, biotin, vitamin C, and more?
http://www.webmd.com/content/Article...m?pagenumber=1
http://www.holisticonline.com/Remedi..._loss-diet.htm

Hair loss can also be autoimmune, and given you already have one autoimmune disease... thyroid disease... this seems a possiblility? Alopecia: http://www.emedicine.com/derm/topic14.htm

Thyroid disease, neuromuscular disease, and alopecia areata are all associated with Celiac Disease. In fact, those with autoimmune thyroid disease are at greater risk of having Celiac Disease, and more often than not CD goes undiagnosed. There may or may not be GI symptoms present in someone with CD. If Celiac Disease/gluten sensitivity is found, a gluten free diet may result in hair regrowth (and may improve the course of neurological and other disease as well).

Some great overview articles about Celiac Disease/ Gluten Sensitivity:

Detecting Celiac Disease in Your Patients by Harold T. Pruessner, MD

Gluten-Sensitive Enteropathy (Celiac Disease): More Common Than You Think by David A. Nelson, JR, MD, MS (AAFP)

Gluten sensitivity as a neurological illness, M Hadjivassiliou, et al.

Pertinent pages from The Gluten File:

At Risk Population for Gluten Sensitivity/Celiac Disease

Diagnostic Testing

Type 1 Diabetes and Autoimmune Thyroid Disease


PubMEd:

Celiac disease is frequently associated with other autoimmune disorders but has never been reported in association with alopecia areata. In a routine clinical practice, 3 patients with such an association were observed. In one of the patients, celiac disease was diagnosed after the occurrence of malabsorption symptoms. In the youngest patient, a 14-year-old boy, gluten-free diet resulted in complete regrowth of scalp and body hair. A prospective screening program for celiac disease using antigliadin and antiendomysial antibodies was therefore set up in 256 consecutive outpatients with alopecia areata. Three patients, all completely asymptomatic for intestinal diseases, were found to be positive and underwent biopsy. Histological analysis showed a flat intestinal mucosa consistent with the diagnosis of celiac disease. The results show that alopecia areata may constitute the only clinical manifestation of celiac disease and that the association between these two conditions is a real one because the observed frequency of association is much greater than can be expected by chance. It is suggested that antigliadin and antiendomysial antibodies should be included in the work-up of patients with alopecia areata.
Celiac disease and alopecia areata: report of a new association. PMID: 7557104

Serological screening for coeliac disease in vitiligo and alopecia areata. PMID: 9205530


Maybe a long shot, but I think a blood test to look for CD/GS is warranted.

Cara