Letter to the editor in response to Duan X, et al, CYP4A22 loss-of-function causes a new type of vitamin D-dependent rickets (VDDR1C).

Duan X, et al, report that CYP4A22 loss-of-function causes a new form of vitamin D-dependent rickets. Here we describe the basis for our rejection of their proposal and provide evidence that the CYP4A22 variant that they have identified (c.901del, p.

High dose dietary vitamin D allocates surplus calories to muscle and growth instead of fat via modulation of myostatin and leptin signaling.

Obesity occurs because the body stores surplus calories as fat rather than as muscle. Fat secretes a hormone, leptin, that modulates energy balance at the brain. Changes in fat mass are mirrored by changes in serum leptin.

Dietary vitamin D is a novel modulator of tumor engraftment through regulation of GC protein abundance.

The vitamin D binding protein, the GC protein, is a multifunctional protein that binds circulating vitamin D and also increases macrophage killing of tumor cells. Injecting exogenous GC protein concurrent with experimental tumor implant decreases tumor engraftment rate. Until now serum abundance of this protein was thought to be controlled by estrogen, glucocorticoids and inflammatory cytokines, but, not by vitamin D itself(1, 2).

A Pilot Randomized Clinical Trial of Intranasal Oxytocin to Promote Weight Loss in Individuals With Hypothalamic Obesity.

Context: Hypothalamic obesity is a rare, treatment-resistant form of obesity. In preliminary studies, the hypothalamic hormone oxytocin (OXT) has shown promise as a potential weight loss therapy.

Objective: To determine whether 8 weeks of intranasal OXT (vs 8 weeks of placebo) promotes weight loss in children, adolescents, and young adults with hypothalamic obesity.

Directed Photochemically Mediated Nickel-Catalyzed (Hetero)arylation of Aliphatic C-H Bonds.

Site-selective functionalization of unactivated C(sp)-H centers is challenging because of the ubiquity and strength of alkyl C-H bonds. Herein, we disclose a position-selective C(sp)-C(sp) cross-coupling reaction. This process engages C(sp)-H bonds and aryl bromides, utilizing catalytic quantities of a photoredox-capable molecule and a nickel precatalyst.