Update on the management of vitamins and minerals in cystic fibrosis

Optic neuropathy from hypovitaminosis A in a series of children with severe dietary restrictions

AIM

Hypovitaminosis A is a leading cause of preventable childhood blindness, especially in developing nations. Vitamin A is a fat-soluble essential micronutrient that serves vital functions in the visual system and in regulating bone resorption. We report on a series of four children with mixed nutritional and compressive optic neuropathy and provide a review of the literature.

METHODS

A retrospective observational study of four males (ages 9-12), three with autism spectrum disorder who presented with loss of vision and multiple vitamin deficiencies including hypovitaminosis A.

RESULTS

Patients presented with unexplained visual loss or a change in visual behaviour. All patients had severely restricted diet comprising of predominantly carbohydrates. Two of the four cases demonstrated optic nerve pallor at initial presentation with marked optic atrophy developing in all patients over time. Electrophysiology available in two patients demonstrated optic nerve dysfunction with preserved retinal function. Extensive investigations revealed profound deficiency in multiple vitamins including vitamin A (<0.1-0.2 μmol/L, normal = 0.9-1.7 μmol/L). Three patients also had low vitamin B12 (90-111 pmol/L, normal = 170-800 pmol/L) with normal folate. All four cases had radiological evidence of skull base thickening indicative of low vitamin A. Genetic testing did not find any relevant pathogenic variants.

CONCLUSIONS

Hypovitaminosis A is a crucial form of nutritional deprivation that results in significant visual loss with potential hyperostosis and optic nerve compression exacerbating nutritional optic neuropathy. Additional micronutrient deficiencies usually co-exist and may contribute. Extra vigilance in vitamin replacement is required of clinicians with patients with autism who have restricted diets.

Potential Micronutrient Deficiencies in the First 1000 Days of Life: The Pediatrician on the Side of the Weakest

PURPOSE OF REVIEW

This study is to examine potential micronutrient deficiencies and any need for supplementation in children following specific diet plans in the first 1000 days of life.

RECENT FINDINGS

Optimal nutrition in the first 1000 days of life has a lifelong positive impact on child development. Specific intrauterine and perinatal factors, pathological conditions, and dietary restrictions can represent potential risk factors for micronutrient deficiencies in the first 1000 days of life, which can have negative systemic consequences. Preterm and low-birth-weight infants are intrinsically at risk because of immature body systems. Children affected by cystic fibrosis are prone to malnutrition because of intestinal malabsorption. The risk of micronutrient deficiency can increase in various situations, including but not limited to children following selective dietary regimens (vegetarian and vegan diets and children affected by specific neuropsychiatric conditions) or specific dietary therapies (children affected by food allergies or specific metabolic disorders and children following restricted diet as a part of therapeutic approach, i.e., ketogenic diet for epilepsy). In light of this situation, the micronutrient status in these categories of children should be investigated in order to tailor strategies specific to the individual's metabolic needs, with a particular focus on deficiencies which can impair or delay the physical and cognitive development of children, namely, vitamin B12, vitamin D and folic acid, as well as oligo-elements such as iron, zinc, calcium, sodium, magnesium, and phosphorus, and essential fatty acids such as omega-3. Identification of micronutrient deficiency in the first 1000 days of life and timely supplementation proves essential to prevent their long-term consequences.

Changes in vitamins and trace elements after initiation of highly effective CFTR modulator therapy in children and adults with cystic fibrosis - a real-life insight

BACKGROUND

Highly-effective CFTR-modulator therapy with elexa-/teza-/ivacaftor (ETI) has led to improvements in pulmonary outcomes, sweat chloride, body mass index (BMI) and quality of life in people with cystic fibrosis (CF). Improved uptake of fat-soluble vitamins and micronutrients has been reported for CFTR-modulators but data regarding ETI therapy is lacking.

METHODS

This single-center retrospective study evaluated forced expiratory volume in one second (FEV-1), sweat chloride, BMI, transaminases (AST, ALT), bilirubin, vitamins A, D, E, zinc and selenium in children and adults eligible for ETI. Parameters were assessed before and up to one year after initiation of ETI.

RESULTS

58 patients (median age m = 28 years, SD ± 11.6 years, 51.7% female14 < 18 years old) were included. FEV-1 and sweat chloride improved significantly after ETI. There were no changes in BMI or AST. ALT was increased significantly after 4 weeks of ETI but returned to normal levels in further course. Bilirubin levels remained elevated after ETI. Vitamin A was significantly higher 12 months after ETI. No changes were found for vitamins D, E, zinc and selenium.

CONCLUSIONS

This study adds to the evidence that improvements of some fat-soluble vitamin levels can be found after ETI. No changes regarding micronutrients were noted. Individualized follow-up and supplementation are recommended.

Fat malabsorption in pancreatic cancer: Pathophysiology and management

Exocrine pancreatic insufficiency (EPI) is common in pancreatic ductal adenocarcinoma (PDAC) and may lead to significant nutrition compromise. In the setting of cancer cachexia and gastrointestinal toxicities of cancer treatments, untreated (or undertreated) EPI exacerbates weight loss, sarcopenia, micronutrient deficiencies, and malnutrition. Together, these complications contribute to poor tolerance of oncologic therapies and negatively impact survival. Treatment of EPI in PDAC involves the addition of pancreatic enzyme replacement therapy, with titration to improve gastrointestinal symptoms. Medical nutrition therapies may also be applicable and may include fat-soluble vitamin replacement, medium-chain triglycerides, and, in some cases, enteral nutrition. Optimizing nutrition status is an important adjunct treatment approach to improve quality of life and may also improve overall survival.

Cystic fibrosis and fat malabsorption: Pathophysiology of the cystic fibrosis gastrointestinal tract and the impact of highly effective CFTR modulator therapy

Cystic fibrosis (CF) is a progressive, genetic, multi-organ disease affecting the respiratory, digestive, endocrine, and reproductive systems. CF can affect any aspect of the gastrointestinal (GI) tract, including the esophagus, stomach, small intestine, colon, pancreas, liver, and gall bladder. GI pathophysiology associated with CF results from CF membrane conductance regulator (CFTR) dysfunction. The majority of people with CF (pwCF) experience exocrine pancreatic insufficiency resulting in malabsorption of nutrients and malnutrition. Additionally, other factors can cause or worsen fat malabsorption, including the potential for short gut syndrome with a history of meconium ileus, hepatobiliary diseases, and disrupted intraluminal factors, such as inadequate bile salts, abnormal pH, intestinal microbiome changes, and small intestinal bacterial overgrowth. Signs and symptoms associated with fat malabsorption, such as abdominal pain, bloating, malodorous flatus, gastroesophageal reflux, nausea, anorexia, steatorrhea, constipation, and distal intestinal obstruction syndrome, are seen in pwCF despite the use of pancreatic enzyme replacement therapy. Given the association of poor nutrition status with lung function decline and increased mortality, aggressive nutrition support is essential in CF care to optimize growth in children and to achieve and maintain a healthy body mass index in adults. The introduction of highly effective CFTR modulator therapy and other advances in CF care have profoundly changed the course of CF management. However, GI symptoms in some pwCF may persist. The use of current knowledge of the pathophysiology of the CF GI tract as well as appropriate, individualized management of GI symptoms continue to be integral components of care for pwCF.

ESPEN-ESPGHAN-ECFS guideline on nutrition care for cystic fibrosis

BACKGROUND

Nutritional status is paramount in Cystic Fibrosis (CF) and is directly correlated with morbidity and mortality. The first ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with CF were published in 2016. An update to these guidelines is presented.

METHODS

The study was developed by an international multidisciplinary working group in accordance with officially accepted standards. Literature since 2016 was reviewed, PICO questions were discussed and the GRADE system was utilized. Statements were discussed and submitted for on-line voting by the Working Group and by all ESPEN members.

RESULTS

The Working Group updated the nutritional guidelines including assessment and management at all ages. Supplementation of vitamins and pancreatic enzymes remains largely the same. There are expanded chapters on pregnancy, CF-related liver disease, and CF-related diabetes, bone disease, nutritional and mineral supplements, and probiotics. There are new chapters on nutrition with highly effective modulator therapies and nutrition after organ transplantation.

Fat-soluble vitamin deficiency and exocrine pancreatic insufficiency among adults with chronic pancreatitis: Is routine monitoring necessary for all patients?

Chronic pancreatitis (CP) is often associated with exocrine pancreatic insufficiency (EPI), which may increase risk for fat-soluble vitamin depletion. Although vitamin D deficiency is widespread among the general population, vitamins A, E, and K deficiencies may more uniquely present in patients with CP. Yet, it is unclear whether fat-soluble vitamin status should be routinely monitored in all patients with CP or limited to those with EPI. The purpose of this review is to describe the laboratory status of vitamins A, E, and K in adult patients with CP and their association with exocrine pancreatic function. Five primary, observational studies met the inclusion criteria for qualitative synthesis. Biochemical deficiencies in fat-soluble vitamins were observed across trials but results varied with respect to whether EPI increased risk. Challenges related to the diagnosis and treatment of EPI along with potential confounders may contribute to the heterogeneity among study results. Although more studies are needed to determine the influence of pancreatic enzyme replacement therapy on fat-soluble vitamin status as well as effective vitamin repletion strategies, clinicians should consider periodically screening for deficiencies in all patients with CP regardless of EPI to avoid associated health effects of vitamin depletion.

Standards for the care of people with cystic fibrosis; establishing and maintaining health

This is the second in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy.

The impact of elexacaftor/tezacaftor/ivacaftor on fat-soluble vitamin levels in people with cystic fibrosis

BACKGROUND

While elexacaftor/tezacaftor/ivacaftor (ETI) has improved the pulmonary health of many people with cystic fibrosis (PwCF), less is known about ETI effectiveness for extra-pulmonary manifestations, including fat-soluble vitamin malabsorption. This study aims to evaluate ETI's impact on vitamin A, D, E, and international normalized ratio (INR, an indirect marker for Vitamin K) serum levels.

METHODS

Retrospective cohort study of PwCF ≥12 years receiving ETI. Vitamin levels up to four years preceding and up to two years following ETI initiation were collected. Pairwise comparisons of vitamin levels pre/post-ETI initiation were made using Wilcoxon signed rank and McNemar's tests. Linear mixed effect models were used to regress vitamin levels on time since starting ETI, ETI use (yes/no), the interaction between time and ETI use, and age.

RESULTS

Two hundred and sixty-four participants met study inclusion, and 169 (64%) had post-ETI initiation vitamin levels. Median vitamin A levels increased from 422.0 to 471.0 mcg/L (p < 0.001), median vitamin D levels increased from 28.5 to 30.8 ng/mL (p = 0.003), and there were no significant changes in median vitamin E or INR. Vitamin A levels rose at a rate of 40.7 mcg/L/year (CI 11.3, 70.2) after ETI start.

CONCLUSIONS

ETI initiation is associated with increased median vitamin A and vitamin D levels, but no change in median vitamin E or INR levels. Ongoing monitoring of vitamin levels after ETI initiation is needed to screen for potential deficiencies and toxicities, particularly in light of case reports of hypervitaminosis A following ETI initiation.

Understanding and addressing the needs of people with cystic fibrosis in the era of CFTR modulator therapy

Cystic fibrosis is a multiorgan disease caused by impaired function of the cystic fibrosis transmembrane conductance regulator (CFTR). Since the introduction of the CFTR modulator combination elexacaftor-tezacaftor-ivacaftor (ETI), which acts directly on mutant CFTR to enhance its activity, most people with cystic fibrosis (pwCF) have seen pronounced reductions in symptoms, and studies project marked increases in life expectancy for pwCF who are eligible for ETI. However, modulator therapy has not cured cystic fibrosis and the success of CFTR modulators has resulted in immediate questions about the new state of cystic fibrosis disease and clinical challenges in the care of pwCF. In this Series paper, we summarise key questions about cystic fibrosis disease in the era of modulator therapy, highlighting state-of-the-art research and clinical practices, knowledge gaps, new challenges faced by pwCF and the potential for future health-care challenges, and the pressing need for additional therapies to treat the underlying genetic or molecular causes of cystic fibrosis.

Impact of elexacaftor/tezacaftor/ivacaftor on fat-soluble vitamin levels in children with cystic fibrosis

BACKGROUND

Children with cystic fibrosis are at risk of fat-soluble vitamin deficiency. CFTR modulators positively effect nutritional status. This study aimed to assess changes in serum vitamins A, D & E after starting ETI therapy to ensure levels were not abnormally high.

METHODS

Retrospective review of annual assessment data over 3½ years, before and after starting ETI in a specialist paediatric CF centre, including vitamin levels.

RESULTS

54 eligible patients were included, aged 5-15 yrs (median age 11.5). Median time to post measurements was 171 days. Median vitamin A was increased (1.38 to 1.63 µmol/L, p<0.001). Three patients (6%) had high vitamin A post-ETI, compared with none at baseline; and 2 (4%) had low levels compared to 4 (8%) at baseline. No changes in vitamins D&E.

CONCLUSIONS

This study found increased vitamin A, sometimes to high levels. We recommend testing levels within 3 months of starting ETI.

Reproductive Counseling and Care in Cystic Fibrosis: A Multidisciplinary Approach for a New Therapeutic Era

With the advent of highly effective modulator therapies, many people with cystic fibrosis (CF) are living longer, healthier lives. Pregnancy rates for women with CF more than doubled between 2019 and 2021, reflecting increases in both planned and unplanned pregnancies. For men with CF, CF-associated infertility can be mitigated with assistive reproductive technology, yet patient knowledge of these challenges and options is variable. Preconception and prenatal counseling for individuals with CF and for parents of children with CF who wish to expand their families requires nuanced discussions to promote informed reproductive decisions, drawing from a combination of standard practice recommendations and CF-specific assessments. This review article synthesizes the current literature and practice recommendations regarding reproductive counseling and care in CF, outlining the role of genetic counseling, carrier screening, teratogen counseling, in vitro fertilization and pre-implantation genetic diagnosis, and careful assessment and management of cystic fibrosis-related diabetes when present. Via a multidisciplinary, patient-centered approach, clinicians can support adults with CF and parents of children with CF as they make informed reproductive decisions and embark on family planning.

Evolving Nutritional Needs in Cystic Fibrosis

The course of cystic fibrosis (CF) as a nutritional illness is diverging since the introduction of highly effective modulator therapy, leading to more heterogeneous phenotypes of the disease despite CF genetic mutations that portend worse prognosis. This may become more evident as we follow the pediatric CF population into adulthood as some highly effective modulator therapies (HEMT) are approved for those as young as 1 year old. This review will outline the current research and knowledge available in the evolving nutritional health of people with CF as it relates to the impact of HEMT on anthropometrics, body composition, and energy expenditure, exocrine and endocrine pancreatic insufficiencies (the latter resulting in CF-related diabetes), vitamin and mineral deficiencies, and nutritional health in CF as it relates to pregnancy and lung transplantation.

Nutrition in children with exocrine pancreatic insufficiency

Exocrine pancreatic insufficiency (EPI) is a condition defined as pancreatic loss of exocrine function, including decreased digestive enzymes and bicarbonate secretion, which leads to maldigestion and malabsorption of nutrients. It is a common complication in many pancreatic disorders. If left undiagnosed, EPI can cause poor digestion of food, chronic diarrhea, severe malnutrition and related complications. Nutritional status and fat-soluble vitamins should be carefully assessed and monitored in patients with EPI. Early diagnosis of EPI is clinically important for appropriate nutritional support and initiating pancreatic enzyme replacement therapy (PERT) which could significantly improve patient outcomes. The evaluation of nutritional status and related unique management in children with EPI will be discussed in this review.