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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Vitamin D in children with cystic fibrosis

Dr Malcolm Brodlie and colleagues from the Great North Children’s Hospital in Newcastle, United Kingdom, have recently reported on the vitamin D levels of children with cystic fibrosis enrolled in their regional center following an internal change in vitamin D recommendations and policy.

Brodlie M et al. Vitamin D in children with cystic fibrosis. Arch Dis Child, 2012.

Vitamin D is particularly important in cystic fibrosis (CF) because of the number of complications in CF, like respiratory infections, diabetes and bone disease. In fact, earlier this year, we reported on a randomized controlled trial where vitamin D improved quality of life and reduced the risk of death in patients with CF.

In 2007, the CF Trust Bone Mineralisation Working Group recommended a target of 32-60 ng/ml for vitamin D levels in children with CF. The same range was also suggested by the CF Foundation Consensus Group on Bone Health.

Dr Brodlie and colleagues examined vitamin D levels in 78 pancreatic insufficient CF children from their regional center in 2008. Doctors characterize CF as either pancreatic insufficient (making up 80% of cases) or pancreatic sufficient (20% of cases). Children that are pancreatic insufficient may need higher doses of vitamin D because they have intestinal malabsorption. Here, the researchers found that the children had a median level of 20.6 ng/ml, ranging between 3.2-36.4 ng/ml. Only 10% of the children met the target of 32-60 ng/ml.

During this measure, the regional center had a policy to recommend 800 IU/day supplementation. In February of 2009, however, the center changed their policy to either 3,800 IU/day or 800 IU/day plus 20,000 IU/week. The researchers wanted to know if this new policy helped more patients reach the target of at least 32 ng/ml.

So in 2010, the researchers looked at vitamin D levels in 72 pancreatic insufficient CF patients (not necessarily the same children from 2008). This time, the median level was 28.8 ng/ml with a range of 10.4-63.2 ng/ml, a significant increase in levels from two years prior. Still, only 51% of the CF children met the target of at least 32 ng/ml.

This study highlights a few things. From a clinical perspective, public recommendations do not always meet the needs of patients, and so it is up to the clinic to set a policy that does meet their needs. This point was stressed among researchers who felt the US Food and Nutrition Board’s 2010 vitamin D recommendation of 600 IU/day for adults was too low and should not necessarily influence the recommendations of health care providers.

Here, the researchers had a policy of 800 IU/day, close to public recommendations. On this regimen, 90% of patients did not meet a level of 32 ng/ml as recommended by two CF organizations. Also, based on the median level, we can ascertain that even on 800 IU/day, only half of the CF patients were even able to achieve the US Food and Nutrition Board’s minimal blood level recommendation of 20 ng/ml.

Which leads to the second point; 800 IU/day is not enough. In half the malabsorption cases, even 3,800 IU/day was not enough. The ages of the children ranged from 1-17 years old. I would guess that the 3,800 IU/day recommendation was more likely to meet the needs of younger, light weight children, as opposed to the older, heavier children. It is important to develop a policy that factors in the weight of patients. The Council, for example, has a recommendation of 1,000 IU/day per 25lbs of body weight for healthy children, let alone children malaborption issues.

Lastly, while the effectiveness of the center’s new policy of 3,800 IU/day did not optimally raise levels, it was a clear improvement in the levels achieved from their prior policy of 800 IU/day. This shows that it is a worthwhile and efficacious effort for health organizations to set recommendations divergent from what is recommended by government agencies like the US Food and Nutrition Board. In the case here, recommendations set by CF organizations trickled down to the clinical level.

  About: Brant Cebulla

Brant Cebulla was a staff member for the Vitamin D Council from May 2011 to April 2014. He has keen interests in nutrition and exercise.