Infant and Maternal Vitamin D Supplementation: Clinician Perspectives and Practices.

INTRODUCTION: Rates of infant vitamin D supplementation fall short of guideline recommendations. We explored this discrepancy from the clinician perspective as they advise and affect this important intervention to prevent rickets. We compared infant and high-dose maternal vitamin D supplementation prescribing attitudes and practices between infant-only clinicians (IC) and clinicians who care for mothers and infants (MIC). METHODS: We surveyed clinicians in departments of family medicine, obstetrics/gynecology, primary care pediatrics, neonatology, newborn nursery, and members of vitamin D and rickets working groups and a social media group for lactation medicine providers about their perspectives and practices regarding vitamin D supplementation. RESULTS: 360 clinician survey responses were analyzed. In current practice, IC were more likely than MIC to recommend vitamin D supplementation to exclusively (P < .001) and partially breastfed infants (P = .005). MIC were more likely than IC to discuss infant and high-dose maternal supplementation options and let the parents/caregivers choose (34.7%, 22.0%, P = .009). If supplementing the mother with high-dose vitamin D or the infant directly each provided adequate vitamin D in the infant, MIC were more likely than IC to think that supplementation of the mother would be preferred by parents/caregivers (63.0%, 45.2%, P = .003), improve adherence (66.5%, 49.4%, P = .006), and promote breastfeeding (54.7%, 36.5%, P = .001); they were also more likely to recommend supplementation of the mother (17.7%, 8.9%, P = .04). CONCLUSIONS: MIC are more likely than IC to embrace high-dose maternal vitamin D supplementation to provide adequate vitamin D for infants. This highlights an opportunity for further education of clinicians about this option.

Somatic and germline CACNA1D calcium channel mutations in aldosterone-producing adenomas and primary aldosteronism.

Adrenal aldosterone-producing adenomas (APAs) constitutively produce the salt-retaining hormone aldosterone and are a common cause of severe hypertension. Recurrent mutations in the potassium channel gene KCNJ5 that result in cell depolarization and Ca(2+) influx cause ∼40% of these tumors. We identified 5 somatic mutations (4 altering Gly403 and 1 altering Ile770) in CACNA1D, encoding a voltage-gated calcium channel, among 43 APAs without mutated KCNJ5. The altered residues lie in the S6 segments that line the channel pore. Both alterations result in channel activation at less depolarized potentials; Gly403 alterations also impair channel inactivation. These effects are inferred to cause increased Ca(2+) influx, which is a sufficient stimulus for aldosterone production and cell proliferation in adrenal glomerulosa. We also identified de novo germline mutations at identical positions in two children with a previously undescribed syndrome featuring primary aldosteronism and neuromuscular abnormalities. These findings implicate gain-of-function Ca(2+) channel mutations in APAs and primary aldosteronism.