The identified disparity to prescribe vitamin B12 for borderline deficiency may be described as an attempt in the GP collective to seek a balance between being the patient's or the society's doctor. We propose that relevant authorities try to reduce this disparity by describing a management strategy for borderline vitamin B12 deficiency. Key points General practitioners hold different thresholds for commencing supplementation in cases of borderline vitamin B12 deficiency. Participants from Australia were asked to fill out a cross-sectional survey to explore factors which correlate with the propensity to prescribe in clinical practice. Our study identified that patient demands and a practitioner's perception of whether there is an overuse of vitamin B12 in the community influenced the propensity to treat for deficiency. The results give insight into reasons for initiating supplementation, and will help inform general practitioners on their current management.

Idiopathic hypogonadotropic hypogonadism (IHH) refers to a family of genetic disorders that affect the production and/or action of gonadotropic-releasing hormone, resulting in reduced serum levels of sex steroids. This condition has a prevalence of 1–10 cases/100 000 births and is characterised by the absence of spontaneous pubertal development. In women, the condition is characterised by the onset of normal adrenarche, with the absence of thelarche and menarche. Pubertal induction for breast development and uterine growth with oestradiol, and sequential maintenance of a normal menstrual cycle and adequate oestrogen for bone health, with an oestrogen and progesterone, is considered first-line treatment. Pregnancy can be achieved in patients who have received and responded to treatment with ovulation induction with exogenous gonadotrophins. Advances in genetic testing have led to increased research and understanding of the underlying genetics of IHH with gene mutations described in up to 50% of all IHH cases.