A new study published by the American Academy of Pediatrics (AAP) found that children allergic to cow’s milk have lower bone density than normal. Their dietary calcium intake does not meet the daily recommended amount of calcium. The cross-sectional study also found that only less than one-half, 37% to be exact, of all the children in the study were regularly consuming vitamin D and calcium supplements. It was concluded that pre-adolescence children with cow’s milk allergy (CMA) are not receiving enough calcium and vitamin D through their diet. For such children consulting a nutritionist for alternative and nutritiously beneficial dietary options is the best strategy.

Cow’s Milk Allergy (CMA) is the most common type of food allergy found in American infants and young children. It is estimated that 2.5% of children younger than three years of age are currently suffering from milk allergy with the condition developing in the first year of life due to a high level of cow’s milk antibodies in blood. Many children outgrow the condition but it leaves lasting effects on their bones due to deficiency during the growing age. The sensitivity and symptoms of CMA vary from person to person. Some people only have mild reactions such as hives, but others can also develop severe reactions like the life-threatening anaphylaxis.

The only treatment for children with CMA is to avoid cow’s milk from diet completely. However, CMA leaves a harmful impact on the bone mineral density (BMD) of such individuals due to the deficiency of chief bone nutrients during intensive skeletal growth in childhood. Some 27% of American adults with CMA develop osteoporosis. The US National Institutes of Health (NIH) recommends children between the ages of 1 to 3 years old need at least 700 mg of calcium every day, and from 4 to 8 years of age the requirement increases to 1,000 mg per day, with a further increase to 1,300 mg between 9 to 13 years of age.

The study was carried out on 52 children with persistent CMA at the University of Montreal in Canada, between 2011 and 2014. An additional 29 children with non-cow’s milk food allergies (NCMA) were also included in the research as the control group. Dr Anne Des Roches at the Centre Hospitalier Universitaire Sainte-Justine Research Center in the allergy division was the lead author of the study. The aim of the study was to assess whether children with either CMA or NCMA are consuming calcium and vitamin D supplementation.

“Milk allergy is one of the most frequent food allergies in infants,” Dr Des Roches told Reuters Health through email. “Infants can have formula instead, and older children may have soy milk, rice milk or almond milk, but these may be less nutritive. For all children with milk allergy, a consultation with a nutritionist is always a good thing.”

The researchers took measurements of the children’s total body composition along with their lumbar spine BMD. The dual energy radiograph absorptiometry technique was employed to determine the spinal BMD. Similarly, blood plasma tests were also carried out to determine the levels of plasma 25-hydroxyvitamin D concentration. Dietary questionnaires, like the Food Frequency Questionnaire, were also given to the parents of the children to review the children’s dietary calcium and vitamin D consumption.

The results showed that more than 60% of the children with CMA did not meet their daily levels of recommended dietary calcium, while only 25% of the children with NCMA had the same status. Only less than 15% of children from both the test and control group showed adequate levels of vitamin D in their system, with 89% of the children from the test group and 93% from the control group showing deficiency. In 6% of the children with CMA, the bone mass was found to be very low, compared to the children from the control group. Children from the test group also displayed lower levels of calcium intake.

“The important message is that these children should be followed preventively to be sure that they take sufficient calcium and vitamin D to have strong bones and avoid bone problems,” Des Roches said. “Otherwise, these kids are in very good health.

The study was the first of its kind since intake and obedience to calcium and vitamin D supplementation along with measurement of bone density and vitamin D levels had never been documented before. Dietary calcium is important for the maintenance of a positive calcium balance which includes mineral homeostasis and bone mineralization, processes which ensure bone mass growth. Studies have shown peak bone mass development during childhood is associated with lower risk of osteoporosis and fracture later in life. Vitamin D is also essential for the proper absorption of vitamin D in the intestines.

Since the research is based on the children in Quebec, Canada, who do not have proper access to sunlight and a relatively low standard of public health system, the complicated situation may be considered as a limitation when comparing the results for the masses. In Canada vitamin D fortification is already mandatory which questions the reliability of the test results as a comparison standard. In the same way, bone mass is also dependent on genetic inclination and the current study did not cover that aspect.

The FFQ used was designed to only assess the habitual intakes of calcium and vitamin D, and did not document the levels of any other key bone nutrients. Other than calcium, key bone nutrients include protein, magnesium, phosphorus, potassium and zinc. The correlation between all the bone nutrients is very important for proper formulation of dietary standards.