ARPKD/CHF and Bone Health
Bone Health in Autosomal Recessive Polycystic Kidney Disease and Congenital Hepatic Fibrosis
by Linda Bevec
Six months after my daughter’s kidney transplant she began to complain of leg pain. The pain would be mild and achy at times, but so severe at other times that she’d cry and beg for Tylenol. She’s 10 years old and has been enjoying life with a healthy kidney so I assumed the leg pain might be due to growing pains or her increased activity level. Then we began to notice that her knees were turning inward and she limped when she walked. After spending a day at an area amusement park she was in tears and the pain became unbearable. So I made an appointment with a pediatric orthopedic doctor and he ordered x-rays on both legs from the hips down. The x-rays revealed that our daughter had mild rickets caused by the early years of her life living with ARPKD/CHF and poor functioning kidneys. Even through she had taken calcium and vitamin D supplements off and on over the years, it wasn’t enough to prevent significant bone damage and she will now require surgery on both knees to straighten her legs.
Rickets is caused amongst other things by a deficiency of vitamin D, calcium or phosphate. Infants and children with ARPKD/CHF are at risk for developing rickets if vitamin D, calcium and phosphate levels are not closely monitored. Symptoms and signs of rickets include bone pain, delayed teeth formation, short stature, skeletal deformities (bowlegs, knock knees, abnormally shaped skull), and decreased muscle strength. Treatment of rickets depends upon the cause, but the first step usually involves correcting any abnormal levels of calcium, phosphate, or vitamin D with supplements.
Vitamin D is a fat-soluble vitamin and can be found in foods such as eggs, fish, cod liver oil, fortified milk and orange juice and cereals – the sun’s rays also is a supplier of vitamin D!
Vitamin D is one of the key nutrients that safeguards the absorption of calcium and phosphorous. These two minerals are required for the growth and health of strong, healthy bones. Working together with our intestines, vitamin D helps to absorb these minerals which can be later transferred to our bones. Some research has revealed that the vitamin may also play a part in keeping the nervous and immune systems in good working order. If your kidneys aren’t working well then calcium is not well absorbed or transferred to our bones and phosphate is not well excreted by the kidneys.
The most common diseases brought on by Vitamin D deficiency is rickets in children and osteomalacia in adults. Rickets in children results in bones that are softer and weaker than normal bones. This softness paired with the weight of the upper body can create either a bowed or knock knee appearance in the legs. Other health problems from Vitamin D deficiency include a weakened immune system, muscular/bone pain, weight loss and insomnia.
Be sure to talk to your nephrologist about close monitoring of your or your child’s serum levels of phosphorous, vitamin D, calcium and parathyroid (PTH) hormone and to adjust supplements accordingly. Early detection and treatment can hopefully prevent bone disease, pain and surgery down the road.
