Why is bone health important in childhood?

Bones undergo changes throughout our lives, as old bone is broken down and new bone forms. But the most important time for building a strong skeleton is during childhood and adolescence. Bone strength depends on both the size of the bones and the amount of mineral they contain.

The greatest gains in bone size and mineral content occur in adolescence. At puberty, hormonal changes take place that start sexual maturity and speed up bone growth. Bones not only get longer and wider, they also get denser. People reach their peak bone mass, or maximum bone size and density, by their late teens or early twenties. As early as age 30, some bones begin to slowly lose mass.

The more bone mass we “Bank” in childhood and adolescence, the better we withstand the inevitable bone losses and the better protected we are from osteoporosis and bone fractures later in life.

What affects children’s bone health?

The genes we inherit, our hormones and our lifestyle all affect our peak bone mass. Genetic factors have the greatest influence on peak bone mass, but to reach his or her “genetic potential,” a child needs adequate levels of certain hormones along with healthy eating and exercise habits.

Growth hormone and the sex hormones estrogen and testosterone at puberty are essential for building bone mass in both boys and girls. Maintaining a healthy weight and getting enough vitamin D, calcium, protein, and physical activity are also key to bone health. Calcium is the main mineral in bone, and vitamin D helps the body absorb calcium. Weight-bearing exercise, such as running and jumping, helps build muscle and bone strength.

Adolescent girls need to be moderate in their approach to diet and exercise. Menstruation can stop in girls who exercise excessively or are extremely underweight (as in anorexia). Girls who never start their periods or stop menstruating often have low estrogen levels, which can harm their bone health.

Is your child getting enough vitamin D and calcium?

Vitamin D. Most of our vitamin D is produced when our skin is exposed to sunlight. Children get vitamin D from playing outdoors, but it’s hard to tell if they’re getting enough. Since few foods naturally contain vitamin D, most milk and infant formula are fortified (meaning vitamin D is added).

Infants, children, and adolescents need at least 400 IU (international units) of vitamin D each day. Children of all ages who do not get 400 IU a day from their diet should take a supplement, prescribed by their doctor.

Children and adolescents with dark skin, limited sun exposure, or certain chronic diseases are more likely to be deficient in vitamin D. A simple blood test can check for vitamin D deficiency.

Calcium. Pregnant and breastfeeding women need at least 1,000 mg of calcium each day, along with adequate vitamin D, to support their own and their babies’ bone health. The recommended daily calcium intake for children and adolescents varies by age:

0-6 months         210 milligrams (mg)

7- 12 months      270 mg

1-3 years            500 mg

4-8 years            800 mg

9-18 years          1,300 mg

What should you do with this information?

Set an example for your child by modeling good bone health habits. Keep calcium rich foods on hand and encourage physical activity. Talk about your child’s bone health whenever you consult your pediatrician. Ask if your child needs nutritional supplements or treatments for an underlying medical condition. If your child has a hormone related disorder that might threaten bone health, you should consult an Endocrinologist, a specialist in the field, about whether hormone treatment is needed.

]]> http://www.diabetesendocrinology.in/2010/02/19/bone-health/feed/ 0 http://www.diabetesendocrinology.in/2009/04/28/hypercalcaemia/ http://www.diabetesendocrinology.in/2009/04/28/hypercalcaemia/#comments Tue, 28 Apr 2009 09:54:04 +0000 admin http://www.diabetesendocrinology.in/?p=144 What is hypercalcaemia?

Hypercalcaemia refers to high levels of calcium in the blood above the normal range of 8.5-10.2 mg/dl.

Is hypercalcaemia a cause of concern?

Yes, it is a cause of concern as it can have many effects on the human body. The symptoms can be diverse and depend on blood calcium levels

Initially symptoms are nonspecific Excess urine and thirst Loss of appetite Depression Muscle weakness Anorexia and nausea Constipation Fatigue Heart problem Pancreatitis

At higher levels Abdominal pain Vomiting Dehydration Lethargy Heart problem Pancreatitis Osteoporosis Coma

What are the causes of hypercalcaemia?

Primary hyperparathyroidism: Overactive parathyroid gland is the most common cause of hyperparathyroidism. It affects females more commonly than males and is more common in the age group of 50 – 60 years.

Other causes are:

• Malignancy is the most common cause of hypercalcaemia.

• Granulomatous conditions -such as sarcoidosis and tuberculosis

• Endocrine conditions – such as thyrotoxicosis, phaeochromocytoma and primary adrenal insufficiency

• Drugs- such as thiazide diuretics, vitamin D and vitamin A supplements

• Familial- e.g. familial hypocalciuric hypercalcaemia

• Tertiary hyperparathyroidism – Post Kidney transplant or chronic dialysis

• Other: e.g. prolonged immobilization, milk-alkali syndrome, AIDS.

What are the investigations required?

a. Fasting blood sample for:

1. Calcium

2. Phosphorous

3. Alkaline phosphatase

4. PTH levels

5. Vit D levels

6. Renal function tests

b. 24 hour urine calcium levels

c. If the PTH is raised, technetium scan of the parathyroid gland is required to localize the adenoma together with an assessment of bone mineral density

What are the treatment options available?

Medical management
Treatment for acute hypercalcaemia should be initiated in hospital and will include

• Increasing the circulating volume and hydration with saline

• Once circulating volume is normal, addition of a loop diuretic e.g. furosemide

• Biphosphonates such as pamidronate and zoledronic acid or salmon calcitonin may be used to reduce bone turnover

• Plicamycin, gallium nitrate and prednisolone are also occasionally used in specialist settings

• In severe cases haemodialysis may be effective

• Asymptomatic patients with PTH mediated hypercalcaemia which doesn’t meet the recognised criteria for surgery may be treated conservatively with regular monitoring of bone density, renal function and serum and urinary calcium levels

• Reduce patients intake of calcium

• Mobilize a bed bound patient

Surgical management:
Indications

• Serum calcium >15mg/dl

• Urinary calcium excretion >400mg/day

• Bone density reduced at any site to a T score <-2.5

• Creatinine clearance reduced by 30%

• Age >50years

Surgical procedure will include removal of the affected portion of the gland by a surgeon.

Are there any complications that can arise after surgery?

Transient, mild hypocalcaemia is common after parathyroidectomy. The commonest cause of hypocalcaemia following parathyroidectomy remains transient hypo-parathyroidism due to suppression of the remaining parathyroid glands by preoperative hypercalcaemia. In fact surgeons are reassured by hypocalcaemia that develops transiently that the adenomatous gland has been removed.

In an entity called as hungry bone syndrome there is a rapid influx of calcium into the bones, which have been deprived of calcium, causing more prolonged hypocalcaemia. With the increased detection of hyperparathyroidism in the asymptomatic stage, primary hyperparathyroidism is being treated before the development of parathyroid bone disease and the incidence of hungry bone syndrome is falling.

Low level of Calcium in the blood is called Hypocalcaemia. Normal blood Calcium is 8.5 – 10.2 mg/dl. In normal health blood calcium is maintained in this range and the normal mechanism is that most of the Calcium is bound to albumin (proteins) and hence before assessing the normal calcium levels , the albumin levels have to be known.

Why is it important for blood Calcium to be normal ?

Calcium is important for a variety of normal physiological activities like muscle contraction, nerve conduction, blood coagulation and release of enzymes & hormones. When the level of blood calcium falls theses activities can be affected

What are the symptoms/ signs of hypocalcaemia?

The symptoms of hypocalcaemia are as follows:

Nerve function	Mental status	Skin changes	Cardiac changes
Fatigue	Confusion	Dry skin & nails	Ventricular arrhythmias
Anxiety	Psychosis	Brittle nails	Prolonged QT interval
Muscle cramps		Atopic eczema	Torsadepointes
Polymyositis		Psoriasis
Paraesthesias		Enamel hypoplasia

The clinical signs of hypocalcaemia are:
1. Chovstek’s sign is elicited by tapping over the facial nerve approximately 20 mm anterior to the ear lobe below the zygomatic arch.

2. Trosseau’s sign represents carpal spasm secondary to ischaemia of the ulnar and median nerves in response to inflation of sphygmomanometer to 20 mm of Hg over systolic blood pressure.

CHOVSTEK’S SIGN TROUSSEAU’S SIGN

What are the causes of hypocalcaemia?

While there are many causes of low calcium, the most common is due to destruction to the parathyroid glands, either due to a developmental defect in the fetus or after neck surgery or irradiation. Antibodies to tissue components of the parathyroid gland can also develop, affecting the ability of the glands to make parathyroid hormone.

Other causes include

1. • Vitamin D deficiency – nutritional lack, malabsorption, liver disease, receptor defects

   • Vitamin D resistance (rickets) – renal tubular dysfunction (Fanconi’s syndrome) or receptor defect

   • PTH resistance (pseudo hypoparathyroidism), hypomagnesaemia

   • Drugs – calcium chelators (citrate in blood transfusion)

   • Bone resorption inhibitors (bisphosphonates, calcitonin, plicamycin)

   • Drugs affecting vitamin D (phenytoin, ketaconazole), foscarnet

   • Others – acute pancreatitis, acute rhabdomyolysis, massive tumour breakdown, osteoblastic metastases, toxic shock syndrome, hyperventilation

What are the investigations necessary?

Fasting blood sample for

1. S.calcium

2. S.Phosphate

3. Alkaline phosphate

4. PTH

5. S.Magnesium

6. Vitamin D levels

7. Liver function tests

8. Renal function tests

What is the treatment of hypocalcaemia ?

Hypocalcaemia is an endocrine emergency. During the acute period IV calcium infusion is to be given. This can be followed later on by calcium and Vitamin D supplementations. During the acute period blood calcium will have to be checked very frequently, once stabilized, less frequent monitoring is sufficient. Once stable, calcium will have to be checked less frequently say once or twice a year. Once a dose change is made it is advisable to check calcium two to three weeks later.

Are there any risks of treatment?

The main risk of treatment with Vit.D/calcium supplementation is that the blood level of calcium can go up above normal. This should not happen if the medication has been started after the right diagnosis and if the monitoring is regular. Once there are symptoms of high blood calcium like thirst, increased urination, constipation etc. it is advisable to get a blood level checked immediately and adjust the calcium supplementation.

Calcium is important for the human body as it helps in

1. Muscle contraction

2. Nerve conduction

3. Blood coagulation

4. Release of enzymes & hormones

How is the blood Calcium regulated?

A very delicate balance between the blood & the bone maintains this level. Of the total body calcium 99% is stored in the bone; the remaining 1% is in the blood. The parathyroid glands help in maintaining this level. Parathyroid glands are situated next to the Thyroid gland, that is why they are called that but they have no relation to thy Thyroid gland or Thyroid hormone.

The parathyroid glands are four small glands situated on either side of the thyroid gland. They produce a hormone called as parathyroid hormone (PTH), which helps in maintaining blood calcium levels. Vitamin D & sun expossure also play an important role in maintaining blood calcium levels.

What is the daily requirement of Calcium?

The National Osteoporosis Foundation recommends that all adults have a daily dietary intake of 1000 to 1200 mg of calcium each day.

What are the foods rich in Calcium?

The main sources of calcium in the diet are dairy products (milk, yogurt, cheese, curd) and green leafy vegetables.

Quantities of foods containing 500 mg of Elemental Calcium:

• Milk – 14 oz.

• Calcium fortified Milk – 8 oz.

• Vanilla milkshake – 12 oz.

• Yogurt, plain, low-fat – 10 oz.

• Ice cream – 2 3/4 cups

• Custard – 1 2/3 cups

• Cheese – 1 1/4 cups

• Tofu – 1 3/4 cups

• Cheese pizza – 3 slices

Who are the people at risk for developing Calcium related problems?

Osteoporosis risk factors that cannot be changed are:

• Being female

• Postmenopausal

• Having a small skeleton

• Being Caucasian / Asian

• Family history of osteoporosis and fractures

• Advanced age

Osteoporosis risk factors that can be changed are:

• Medications with negative affects on bone

• Inadequate or excessive intake of nutrients

• Sedentary – no weight bearing activity

• Excessive exercise

• Low body weight

• Cigarette smoking

• High alcohol consumption

What can be done to lower the risk of osteoporosis?

All to lower their risk can do two very important things: be physically active and take adequate calcium. If a person picked the one thing that would have the greatest impact on his/her life and lower the risk for a number of late effects and common adult health problems, it would be to make a lifetime habit of being physically active. Regular exercise, four times a week for about thirty minutes, makes a huge difference in the strength of our bones.

Suggestions for exercise:

• Simple walking is GREAT!

• If you are not active, begin slowly and build up each week

• Alternate the types of exercise to keep it fun.

• Use other ways to increase your activity level. Use the stairs rather than the elevator. When weather permits, park a few blocks from the office and walk.

Who should take Calcium supplements?

All people with an increased risk of osteoporosis should take Calcium supplementation.

Calcium supplementation is available in various forms. The RDA for calcium intake is based on the amount of elemental calcium in the supplement taken. The most commonly available is the Calcium carbonate; 500mg of this contains only 200mg of elemental Calcium. Hence at least 1gm of this is needed to give you approximately 400mg of elemental calcium.

There are other supplements which are available which contain vit.D along with calcium. While taking these supplements, a word of caution about the blood level of Calcium, as they tend to go up and cause other problems.