Vitamin D intoxication in two brothers: be careful with dietary supplements

Abstract

Vitamin D (VitD) intoxication, a well-known cause of hypercalcaemia in children, has renal, cardiac and neurological consequences. Iatrogenic or accidental administrations are the most common causes. We present two cases of hypervitaminosis D due to over-the-counter VitD supplement self-medication. A 12-year-old boy was hospitalised for abdominal pain, constipation and vomiting. Routine biochemistry indicated severe hypercalcaemia and renal failure. Plasma 25-OH VitD level was very high and parathyroid hormone was suppressed. Renal ultrasound showed nephrolithiasis. Hydration, diuretics and prednisone induced a progressive reduction of calcium levels. His brother, who was receiving the same treatment, was hospitalised although asymptomatic. Normal serum calcium and renal function were revealed, while 25-OH VitD was high and parathyroid hormone was suppressed. Renal ultrasound was within the normal range. Examination of the VitD content of the over-the-counter supplement revealed a higher amount than declared. VitD administration implies several risks and must be prescribed only when needed and under strict medical control.

A review of the growing risk of vitamin D toxicity from inappropriate practice

“… reported three cases of vitamin D intoxication with severe hypercalcaemia, where the patients had been treated with a vitamin D formulation with a stated dose of 600 IU, whereas, in fact, the actual content was 52 800 IU. Similar manufacturing errors, producing serious toxicity and hospitalization, has also been reported in children . Seven paediatric cases of hypercalcaemia due to vitamin D intoxication were reported in association with a fish oil supplement, where the stated dose was roughly 4000 times less than the actual dose ; in one of these cases, an infant in whom the stated daily dose was 2000 IU day –1 was actually taking 6000 IU day –1 .…”

Protective Role of Vitamin D in Renal Tubulopathies

“…The therapeutic use of this compound should be able to inhibit the development of inflammation without interfering with normal homeostasis. Megalin-Cubilin-Amnionless and FGF23-Klotho axes represent two Vitamin D-linked mechanisms that could modulate and ameliorate the damage response at the renal tubular level, balancing Vitamin D therapy with an effect potent enough to contrast the inflammatory cascades, but which avoids potential severe side effects [120].…”

Emphasizing the Health Benefits of Vitamin D for Those with Neurodevelopmental Disorders and Intellectual Disabilities

“…Vitamin D intoxication can result in an elevated serum calcium and serum phosphorus level. Constitutional symptoms include confusion, nausea, constipation, polyuria and polydipsia, decreased heart rate and arrhythmias [ 143 ]. The long-term consequences include soft tissue calcification of the blood vessels, nephrocalcinosis and kidney stones.…”