Related Experiment Video

Updated: Jul 8, 2026

Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells
06:47

Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells

Published on: May 4, 2018

Undercarboxylated osteocalcin and bone mass in 8-12 year old children with cystic fibrosis

M S Fewtrell1, C Benden2, J E Williams1

  • 1MRC Childhood Nutrition Research Centre, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.

Journal of Cystic Fibrosis : Official Journal of the European Cystic Fibrosis Society
|January 8, 2008
PubMed

Insights

Young adults with cystic fibrosis (CF) may have bone disease due to poor vitamin K status. This study found higher levels of undercarboxylated osteocalcin (uc-OC), indicating low vitamin K, linked to lower bone mass in children with CF.

Area of Science:

  • Pediatric endocrinology
  • Bone metabolism
  • Nutritional deficiencies

Background:

  • Cystic fibrosis (CF) is associated with an increased risk of bone disease in young adults.
  • Suboptimal vitamin K status and impaired osteocalcin carboxylation are hypothesized contributors to CF-related bone abnormalities.

Purpose of the Study:

  • To investigate bone mineralization and turnover in children with CF.
  • To assess the relationship between vitamin K status and bone health markers in this population.

Main Methods:

  • Dual-energy X-ray absorptiometry (DXA) for bone mineral density (BMD) and bone mineral content (BMC) of the whole body and lumbar spine (LS).
  • Measurement of 25-OH Vitamin D, parathyroid hormone (PTH), plasma osteocalcin, and pro-peptide of type 1 collagen (P1NP).
  • Assessment of vitamin K status using undercarboxylated osteocalcin (% uc-OC).

Main Results:

  • 20% of CF patients aged 8-12 years had LS BMD Z-scores below -1.0.
  • Size-adjusted bone mass was generally normal, but % uc-OC was elevated and P1NP was decreased compared to reference data.
  • Higher % uc-OC was significantly associated with lower size-adjusted LS bone mineral content and LS bone mineral apparent density.

Conclusions:

  • Children with CF exhibit markers of suboptimal vitamin K status and reduced bone formation, even with normal size-adjusted bone mass.
  • The correlation between LS bone mineral content and % uc-OC supports the hypothesis that vitamin K deficiency is a risk factor for bone disease in CF.
  • Further intervention trials are recommended to confirm these findings and explore therapeutic strategies.
Abstract

Related Concept Videos

Bone Disorders01:29

Bone Disorders

Aging and its effect on bone remodeling is the most common cause of bone disorders. In young and healthy people, bone deposition and resorption happen at an equal rate to maintain optimal bone health.
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Osteoclasts in Bone Remodeling01:31

Osteoclasts in Bone Remodeling

Osteoclasts are cells responsible for bone resorption and remodeling. They originate from hematopoietic progenitor cells present in the bone marrow. Numerous progenitor cells fuse to form multinucleated cells, each with 10-20 nuclei. A single osteoclast has a diameter of 150 to 200 µM. These cells have ruffled borders that break down the underlying bone tissue and release minerals such as calcium into the blood in bone resorption. Osteoclasts cling to bones with their ruffled edges during bone...
Role of Vitamins in Maintaining Bone Health01:25

Role of Vitamins in Maintaining Bone Health

The growth and maintenance of bone are regulated by a combination of nutritional factors, including vitamins, such as vitamin A, B12, C, D, and K.
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Hormones and Bone Tissue01:17

Hormones and Bone Tissue

The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Changes in the Appendicular Skeleton with Age01:09

Changes in the Appendicular Skeleton with Age

The upper and lower limb initially develops as a small bulge called a limb bud, which appears on the lateral side of the early embryo. The upper limb bud appears near the end of the fourth week of development, with the lower limb bud appearing shortly after.
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Bone Remodeling01:40

Bone Remodeling

Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.