Irish Children With PWS Found to Have Vitamin, Nutrient Deficiencies

A study of Irish children with Prader-Willi syndrome (PWS) found that the majority had a normal body mass index (BMI) while also showing evidence of vitamin and nutrient deficiencies.

The results show that more needs to be done to manage — and better balance — the diet of children with PWS to “prevent obesity, avoid micronutrient deficiencies and ensure optimal growth,” according to researchers.

“The broad range of body fat% (10% – 40%) in the present study, highlights the complex nature of this condition, with the possibility of over-restriction in some children and a difficulty in preventing or reducing excessive body fat in others,” the researchers wrote. 

The study, “Dietary intake and growth in children with Prader–Willi syndrome,” was published in the Journal of Human Nutrition and Dietetics. 

In children with PWS, careful food monitoring is necessary to reduce the risks of obesity, micronutrient and nutrient deficiencies, and short stature. Research shows that feeding and growth issues may emerge even before birth, with restricted growth in the womb, and lead to failure to thrive in infants. 

“Strict supervision of dietary intake is one of the cornerstones in the management of a child with PWS,” the researchers said. “However, few studies have examined dietary intake in PWS.”

Now, a team of researchers in Ireland sought to characterize the dietary intake and growth of a group of children with PWS, followed at Tallaght University Hospital, in Dublin. Parents of 19 children — 14 girls (73.7%) and five boys — were asked to record all food and fluid intake in three-day diaries.

The study participants ranged in age from 7 months to 18 years, with a mean age of 7.6. The median age at PWS diagnosis was 2.5 weeks.

Early feeding issues were reported for 15 children and difficulty reaching feeding milestones was noted for seven. All children had required admission to the special care baby unit over a median of seven days, with 13 needing a nasogastric tube for feeding.

A majority of the children (14, or 73.7%) were receiving growth hormone treatment, starting from a mean age of 2.5 years. The remaining five children were in pre-treatment for growth hormone.

BMI, a measure of body fat, was calculated for participants older than 2. Of these 15 children, nine (60%) had a normal weight, three (20%) were underweight, two (13.3%) were obese, and one (6.7%) was overweight.

Body composition was measured for the participants older than 7, with body fat percentages ranging from 10% to 40% and a mean percentage of 25.7%. Of the nine children, four (44%) had excessive body fat, four had a healthy body fat percentage, and one had low body fat.

“Similar to the reported national prevalence of 19% overweight and obesity in the Irish paediatric population, 20% of children in this group were either overweight or obese,” the researchers wrote.

Of the 19 study participants, 17 (89.5%) had completed three-day food diaries. All but one reached 100% or less of their estimated average requirement (EAR) of calories, with a mean percentage of 79%.

Older children achieved significantly lower percentages of their EAR of calories, with a mean percentage of 83.3% for children ages 5 to 12, and 56.4% for those older than 12. That compared with 90.7% for children up to age 5.  

Micronutrient intake — the amounts of vitamins and minerals the children consumed — was assessed in 17 children. Deficiencies in calcium intake were reported in seven children (41.2%), while 16 (94%) were lacking in vitamin D intake. Iron intake was deficient in 13 children (76.5%), and zinc intake in 14 (82.4%). 

Only one child had adequate fiber intake, while 12 (70.6%) had adequate folate and vitamin C intake. Iron deficiency anemia, a common type of anemia, was reported in one child, and vitamin D insufficiency in another. More than half of the study participants (58%) were on micronutrient supplements for nutrient deficiencies.

“The present study showed suboptimal micronutrient intake across all age groups,” the investigators concluded. “We suggest that dietary intake of children with PWS should be assessed regularly throughout childhood to prevent micronutrient deficiencies and support appropriate growth.”

Among the study’s limitations, the team said, were the self-reported nature of food intake, the small sample size, and the lack of a control group.