Recently, physicians in Portugal wrote that an old disease in infants is reappearing. And no, it’s not just rickets we’re talking about. Beyond rickets, very severe low blood calcium levels can cause infants to have severe difficulty breathing, severe muscle spasm, seizures, heart failure and death.
In the present case study, the doctors report on a series of four such children who were either highly pigmented or came from families where members cover almost all of their skin with clothing.
Here were the cases:
- The first infant was brought to the emergency department with infantile spasms (several per minute) and a fixed gaze. Her calcium was very low. So they administered calcium intravenously for 10 days. On day 8, they measured vitamin D, and found that the infant’s 25(OH)D was 9.8 ng/ml. The infant started on 1,800 U/day of D3. No anticonvulsant was used. She also had rickets on x-ray. All symptoms quickly disappeared.
- The second infant, 8 days old, presented with a grand mal seizure. Calcium was low and 25 (OH)D was 8 ng/ml. No rickets was found on x-ray. Calcium was administered. On day 6, the baby was started on vitamin D (calcitriol 25 μg/day). As soon as he started treatment, symptoms remitted.
- The third case was 9 months old, who presented with generalized muscle spasms (tetany) and rickets. Blood calcium was very low and 25(OH)D was 8.9 ng/ml. Calcium was administered and on day 5, the baby was started on vitamin D (cholecalciferol 1,800 U/day). As soon as he started treatment, symptoms remitted and, after 1–2 months, laboratory evaluation was normal. Six months later, the x-rays were normal.
- In the fourth case, a 3 month old infant presented with cardiogenic shock (severe heart failure). His ejection fraction was reportedly 5% (I thought that was incompatible with life). The doctors found that the infant had very low blood calcium. After 16 days of cardiology treatment, someone got a 25(OH)D (5.9 ng/ml) and the infant was started on oral vitamin D (calcitriol 25 mcg/day). The infant probably had prolonged hypocalcaemia which resulted in dilated cardiomyopathy, which led to cardiac failure. This situation was very difficult to compensate, even with high dosage of intravenously administered calcium, until the child was started on vitamin D. After two months of vitamin D, the ejection fraction was normal. Rickets was not found.
Notice one thing. Even though all of the infants had very low 25(OH)D levels, not all of them had x-ray evidence of rickets.
Does this mean they didn’t have rickets? No. In a landmark study, Cohen and colleagues found out some very interesting things about rickets.
First, in a mainly White subset of 30 patients with biopsy proven rickets, they found that none of the cases of rickets had been correctly identified on x-rays by the original radiologists. Even when retrospectively assessing skeletal surveys, two pediatric radiologists only detected biopsy proven rickets 15% of the time.
Furthermore, 87% of these children with biopsy proven rickets were White, showing that the disease is common among Whites. This is important, as too many physicians are only looking for rickets in immigrants or the dark skinned.
In the Cohen study, histological evidence of rickets was present in 22% of the study subjects who had 25(OH)D levels greater than 30 ng/ml. Rickets was absent (on bone biopsy, the diagnostic gold standard) in one infant with a 25(OH)D level of 2.4 ng/ml . This means that rickets cannot be excluded by a 25(OH)D level. Besides 25(OH)D, the other big variable in rickets is adequate calcium intake.
The Cohen study explains the baby Jayden case in England. In this tragic case, the only thing that kept the parents out of prison was the fact their infant died and thus had an autopsy, which discovered rickets that the radiologist had, of course, missed.
Sarah Boseley and Patrick Butler. Baby Jayden case renews concerns over rickets and ‘child abuse’ allegations. Fears grow that rising levels of vitamin-D deficiency may be leading to more cases of rickets being misdiagnosed as child abuse. The Guardian, Friday 20 April 2012.
The conclusion to all of this? As I state often, rickets is more prevalent than we think. For parents with infants, make sure the infant is on 1,000 IU of vitamin D3 a day as well as adequate calcium, which for young infants is 210 mg/day and for infants over six months of age, it is 270 mg/day.