Researchers in Mexico report that vitamin D levels among young children are surprisingly sufficient compared to their United States neighbors.
Dr Mario Flores, MD, PhD, and colleagues conducted the first study assessing vitamin D status of preschool and school-aged children in Mexico in a nationwide sample. The researchers used data from the 2006 Mexican National Health and Nutrition Survey (ENSANUT), with information from 48,000 households from both urban and rural residence areas.
The researchers randomly selected data on 1025 children ages 2 to 12 years from the ENSANUT serum bank. The findings are as follows:
- The mean vitamin D status of pre-school aged children is 31.32 ng/ml and 42.32 ng/ml for children ages 6-12 years.
- Overall, 60% of the children had vitamin D levels above 30 ng/ml, while 15% had levels below 20 ng/ml.
- Forty-five percent of the pre-school age children had vitamin D levels greater than 30 ng/ml while 20% of the children had vitamin D levels <20 ng/ml
- About 70% of school-aged children (6-12 years) had levels above 30 ng/ml, with only 10% having levels below 20ng/ml
- Children living in urban areas were more likely to be deficient when compared with children living in rural areas. Ten percent of rural dwelling children had vitamin D levels below 20 ng/ml while 20% of children living in urban areas had levels <20 ng/ml.
The authors’ results differed from research on similar populations in other countries,
“A representative US sample of 4,558 children ages 1 y to 11 y who participated in the National Health and Nutrition Examination Survey found a mean serum 25-OH-D level of 68 nmol/L [27ng/ml], which is considerably lower than what we observed (94.6 nmol/L [38 ng/ml])…”
The researchers do warn that there may be wide variability in the accuracy of testing methods. However, it is probable that environment and lifestyle factors – such as sun exposure, use of sunscreen, environmental factors and location (nearer the equator) – contributed to the differences observed among the population groups and countries.
Although the vitamin D status of the children represented are more promising than many, the authors call for further research on the topic and the need for further public health awareness about vitamin D deficiency in Mexico.