More Aggressive Vitamin D Treatment May Be Needed in Pediatric Cystic Fibrosis 10-13-08

For most children with cystic fibrosis, vitamin D deficiency is not corrected with recommended treatment, suggesting guidelines are inadequate, researchers said.

Treatment at the recommended 50,000 IU of ergocalciferol once a week was effective for only 33% of children (P=0.80 versus no treatment), reported Peter J. Mogayzel, Jr., M.D., Ph.D., of the Johns Hopkins Hospital, and colleagues in the October issue of the Journal of Pediatrics.

Upping the frequency of dosing to three times a week still left 57% with a deficiency, they found in the retrospective study.

"Aggressive replacement of vitamin D may not be the only approach needed to optimize bone health of patients with cystic fibrosis," they said.

Other options may be even more frequent dosing, use of cholecalciferol instead of ergocalciferol, or UV lights to stimulate endogenous production of the vitamin, Dr. Mogayzel's group suggested.

Vitamin D deficiency is common in children with cystic fibrosis - seen in 46% to 86% in the study -- because of malabsorption of vitamins and minerals, poor nutrition, delayed puberty, decreased activity levels, and treatment with glucocorticoids.

Recognizing this, the Cystic Fibrosis Foundation recommends annual screening for low 25-hydroxy vitamin D preferably in the late fall.

According to the guidelines, vitamin D deficiency with levels below 30 ng/mL should be treated with 50,000 IU of ergocalciferol once a week for eight weeks for children at least five years old and 12,000 IU once a week for eight weeks for younger children.

Recommendations for persistent deficiency are to give 50,000 IU of ergocalciferol twice a week for another eight weeks.

The researchers conducted a retrospective chart review for 262 cystic fibrosis patients under age 21 treated at Johns Hopkins from January 2003 through December 2006.

Early in the study period, 22 children with vitamin D deficiency were treated according to guidelines.

The protocol was amended in March 2004 to go directly to twice weekly dosing because once-weekly was largely ineffective. The new protocol was used for 25 children.

Again, the protocol was found effective for only a few children. So in October 2004, the researchers switched to a regimen of 50,000 IU three times a week -- a strategy similar to one that had worked for adult patients. It was used to treat 181 cases of deficiency.

The rest of the children with deficiency received only the routine vitamin D supplements all were given to meet daily requirements recommended by the Cystic Fibrosis Foundation -- 400 IU/day for patients younger than one year and 800 IU/day for older patients.

Notably, 36.4% of these children had an eventual rebound in vitamin D levels to at least 30 ng/mL without corrective treatment.

None of the corrective treatment protocols were more effective than nontreatment. Success rates with the protocols were:

* 33% with once-a-week treatment (P=0.80 versus no treatment).
* 26% with twice weekly treatment (P=0.34 versus no treatment).
* 43% with treatment three times a week (P=0.22 versus no treatment).

Nor were any of the protocols better than nontreatment for increasing vitamin D levels overall (median increase 14.0, 1.0, and 6.0 versus 5.0 ng/mL, respectively, all P=NS).

Prevalence of vitamin D deficiency peaked in 2003 at 86.5% of patients tested but then declined to a relatively stable rate around 50% (46.2% in 2006).

Deficiency was more common in older children, with a decline in vitamin D levels of 0.44 ng/mL per year of increasing age (P<0.001).

Better lung function predicted less likelihood of deficiency, with an increase of 1.0 ng/mL in vitamin D per 10% higher FEV1 (P=0.004).

"The decrease in prevalence in later years was most likely caused by more aggressive treatment of lower 25-hydroxy vitamin D levels after publication of the Cystic Fibrosis Foundation consensus statement [in 2002]," the researchers noted.

Given that even treatment three times a week was ineffective, the protocol at Johns Hopkins has now moved to 50,000 units of ergocalciferol once a day for four weeks to correct deficiency in both adults and children, they said.

Although the success and toxicity of this regimen remains to be determined, there has been some success in adult patients, Dr. Mogayzel's group said.

"Regardless of the success of this regimen," they added, "it is clear that the current recommendations from 2002 do not provide adequate therapy for vitamin D deficiency in most patients."

Comment:

Remember 30 mins. of full sun with skin contact equals on average 200 IU of Vitamin D. With the current preventative recommendations at 4000-100,000 IU a day you have to get allot of sun daily to meet your requirement. Liver or kidney disease, obesity, osteopenia and osteoporosis, arthritis, parathyroid or thyroid removal, thyroid disease, darker skin, and intestinal malabsorption are all conditions that may require larger doses.

Vitamin D malnutrition may also be linked to an increased susceptibility to several chronic diseases such as high blood pressure, tuberculosis, cancer, periodontal disease, multiple sclerosis, chronic pain, depression, schizophrenia, seasonal affective disorder, peripheral artery disease and several autoimmune diseases including type 1 diabetes.

Much is said about vitamin D in winter; ironically summer is often overlooked. The use of sunscreen with a sun protection factor (SPF) of 8 inhibits more than 95% of vitamin D production in the skin. Recent studies showed that, following the successful "Slip-Slop-Slap" health campaign encouraging Australians to cover up when exposed to sunlight to prevent skin cancer, an increased number of Australians and New Zealanders became vitamin D deficient. Ironically, there are indications that vitamin D deficiency may lead to skin cancer. To avoid vitamin D deficiency dermatologists recommend supplementation along with sunscreen use.

You may need to have your blood calcidiol (25-hydroxy-vitamin D) test done to evaluate your intake and current levels. It takes about 25-29 days to change those levels.