**2. Associated risk factors**

Several contributing factors that control bone mass are diet, lifestyle, levels of cytokines, level of mobilization and physical activity, hormones, genetic factors, and local growth factors. **Table 1** illustrates premature risk factors associated with MBD for both antenatal and postnatal period.

The amalgamation of various nutritional and biomechanical factors results in the precipitation of MBD. Some of them are discussed below:

**87**

interventions [8].

*Calcium and Metabolic Bone Disorders DOI: http://dx.doi.org/10.5772/intechopen.92977*

Prevalence of neuromuscular disorders,

**Antenatal Postnatal**

Preclampsia Liver and kidney disease

**2.1 Vitamin D deficiency**

**Table 1.**

intraventricular hemorrhage

Vitamin D is inevitable for retaining the rate of metabolism in bone. The major function of vitamin D is to boost calcium and phosphorus intestinal absorption by its active metabolite 1,25dihydroxyvitamin D3 along with fostering the continuance of neuromuscular function as well as bone remodeling. Disorders in which this active metabolite is deficient can pose a greater risk of the incidence of bone disorders [6]. Low levels of vitamin D results in decreased absorption of intestinal calcium and phosphorus, with a drop in the level of calcium in serum with an increased synthesis of PTH. A rise in the level of PTH in plasma preserves the level of normal serum calcium by enhancing 1,25-(OH)2D renal development, growing bone yield, and escalating loss in mass of bone. Lack of sufficient intake or a maternal lack of vitamin D is the most leading cause of deficiency of vitamin D. Renal failure or the incidences of hepatic disease, receptor defects, or synthesis of congenital vitamin D are the other instances that cause a vitamin D deficiency. Additionally, two other rare genetic diseases, including vitamin D-dependent rickets type 1 or pseudovitamin D deficiency rickets, are caused due to the mutation in the gene encoding 1α-hydroxylase enzyme (CYP27B1 gene),

*List of premature risk factors associated with metabolic bone disorders for both antenatal and postnatal period.*

Placental insufficiency Use of drugs such as loop diuretics, methylxanthines,

glucocorticoids

Prevalence of bronchopulmonary dysplasia

which is a rate-limiting enzyme involved in the bioactivation of vitamin D.

were not significantly different in the observed group [7].

**2.2 Disorders related to homeostasis of calcium and phosphorus**

A recent report has evaluated vitamin D status and its relationship with skeletal health in 40 healthy adult Nigerians (aged between 21 and 50 years) [7]. An array of physiological parameters were evaluated, which predominantly included markers of bone health, thyroid function and renal function, levels of parathyroid hormone, calcium excretion rates, and serum 25-hydroxyvitamin-D levels. The observed results indicated the fact that approximately 70% of the reported cases had an incidence of vitamin D insufficiency with 25% of the subjects indicated osteopenia, while none of the subjects presented with osteoporosis. The bone mineral density (BMD) T-score for osteopenic subjects was significantly lower than for non-osteopenic subjects. It was also observed that osteocalcin levels in serum were considerably higher in osteopenic subjects versus non-osteopenic subjects; however, a 24-hour calcium excretion was comparable between the two groups. Mean serum 25-hydroxyvitamin-D was lower in subjects with osteopenia compared to nonosteopenic subjects, while parameters for thyroid, renal, and calcium-phosphorus

Disorders related to homeostasis of calcium and phosphorus results in ultimate clinical consequences for neonates. A fine positive balance between calcium and phosphorus is indispensable for sufficient bone growth and maturation. Neonates with persistent malabsorption are at high prospects of poor absorption of calcium, phosphorus, magnesium, or vitamin D, either due to medical or surgical


#### **Table 1.**

*Mineral Deficiencies - Electrolyte Disturbances, Genes, Diet and Disease Interface*

vitamin D deficiency.

withdrawal of estrogens [2].

fragile and fracture-prone.

**2. Associated risk factors**

the treatment of MBD.

rare forms.

in the level of free calcium activates the release and synthesis of PTH, which often leads to calcium reabsorption in the renal tubules, enhanced secretion of calcitriol (vitamin D3) promoting calcium absorption from the intestine, and immediate release of calcium from the skeleton, which contains 99% of calcium in the body. Conversely, in regard to rising levels of calcium in the body, PTH level drops that lead to a decline in the above-stated processes. This balance is seen to be disturbed in various pathological circumstances leading to elevated or low calcium levels. High calcium levels, known as hypercalcemia, and low calcium levels, known as hypocalcemia, are observed in conditions such as hypoparathyroidism and

The most common forms of MBD comprises of osteoporosis, osteomalacia, primary hyperparathyroidism, and fluorosis, while fibrous dysplasia, Paget's disease, osteogenesis imperfecta, and tumor-induced osteomalacia account for its

Osteoporosis is a severe MBD that constitutes to be a serious health issue for older people. It represents a decline in the bone mass per unit volume, leading to significant weaknesses in the bone structure, which ultimately leads to bone deformity/fracture. Osteoporosis is categorized as primary when there is no prominent diagnosis of the disease and secondary when an established contributing cause such as steroid treatment is detectable. Type I (postmenopausal) and type II (age-related) are categorized under primary osteoporosis. Type I osteoporosis incorporates bone loss with the expedited bone mass reduction due to the

Osteomalacia results from curtailed absorption of calcium and phosphate in the intestine due to a deficiency in vitamin D or more rarely due to calcium or phosphate deficiency. Joint pain with fragility in bone and muscular weakness are the

Paget's disease leads to skeletal lesions resulting in progressive bone turnover. The finely constructed bone lacks a natural lamellar framework and has poor quality with effects like bone deformity with prominent fractures and related pain [4]. Hyperparathyroidism results due to excess secretion of PTH, which can be categorized as primary hyperparathyroidism or secondary hyperparathyroidism. Primary hyperparathyroidism occurs due to the raised concentration of calcium in the serum. Research reports show hypercalcemia with an abnormally high level of

Fibrous dysplasia is categorized as a rare form of metabolic disorder in which the bones are covered with irregular structures, which appear as a scar-like fibrous tissue. This deposited structure affects bone structure and integrity, making it more

This chapter discusses in brief about the associated risk factors and diagnosis of MBD along with the preventive measures and the pharmacological approaches for

Several contributing factors that control bone mass are diet, lifestyle, levels of cytokines, level of mobilization and physical activity, hormones, genetic factors, and local growth factors. **Table 1** illustrates premature risk factors associated with

The amalgamation of various nutritional and biomechanical factors results in

common symptoms observed in patients with osteomalacia [3].

alkaline phosphatase and elevated serum PTH [5].

MBD for both antenatal and postnatal period.

the precipitation of MBD. Some of them are discussed below:

**86**

*List of premature risk factors associated with metabolic bone disorders for both antenatal and postnatal period.*
