What is osteomalacia?

In order to make healthy bone, your body needs calcium and vitamin D. Osteomalacia is a condition in which your bones become soft because of a lack of calcium and phosphate, often due to not getting enough vitamin D.

In children, whose bones are still growing, this condition is called rickets.

In people with osteomalacia, a lack of calcium or phosphorus causes bones to become soft, tender, and prone to fracture.Bones in osteomalacia. 

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

Phosphate

An essential mineral required by the body. It is an important part of many processes in every cell in the body, such as combining with calcium to build bones and teeth.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Causes

Your body needs vitamin D in order to absorb calcium and phosphorus, which are both necessary for making strong, healthy bone. When vitamin D, calcium or phosphorus levels are poor, bones can become soft and prone to fractures.

Vitamin D is found in some foods, particularly fish and dairy products (see below for details). However, in most people, vitamin D is produced by the body. Skin cells make a precursor of vitamin D when exposed to sunlight.

The precursors of vitamin D obtained from food and skin cells then get processed in the liver and kidneys to produce the active form of vitamin D.

Precursors of vitamin D come from our skin cells in response to sunlight, and from certain types of food.Vitamin D synthesis in the body. 

Most people have enough vitamin D by some combination of these two routes. However, people who eat a diet poor in vitamin D and who also are not exposed to enough sunlight may be deficient in vitamin D. Problems in processing vitamin D in the gastrointestinal tract, liver or kidneys can also cause vitamin D deficiency.

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

Fractures

A complete or incomplete break in a bone.

Gastrointestinal tract

The membrane-lined series of organs extending from the mouth to the anus through which food passes during digestion.

Kidneys

A pair of organs responsible primarily for regulating the water balance in the body and filtering the blood.

Liver

A large, internal organ of the body, located on the upper right-hand side of the abdomen. The liver has hundreds of distinct functions, including producing bile, regulating the body's metabolism and detoxifying the blood.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Phosphorus

An important mineral that is necessary for growth, formation of bones and teeth and energy metabolism.

Risk factors

Risk factors for osteomalacia include:

  • A diet poor in vitamin D or calcium;
  • Living in areas or conditions where you get very little exposure to sunlight, or regularly wearing clothing that covers nearly all of your body;
  • Having darker skin;
  • Being of an older age;
  • Having a condition that interferes with vitamin D metabolism, including some bowel diseases, kidney or liver problems;
  • Having a condition that interferes with calcium metabolism;
  • Taking certain medications, such as medication for treating osteoporosis [1] , and;
  • Being a breastfed infant whose mother is vitamin D deficient.

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

Kidney

A pair of organs responsible primarily for regulating the water balance in the body and filtering the blood.

Liver

A large, internal organ of the body, located on the upper right-hand side of the abdomen. The liver has hundreds of distinct functions, including producing bile, regulating the body's metabolism and detoxifying the blood.

Metabolism

The sum of all chemical changes that take place within an organism to maintain growth and development and convert food into energy and building blocks.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Bowel

The part of the digestive tract that comprises the small and large intestines.

1. Holick, M.F. (2007). Vitamin D Deficiency. New England Journal of Medicine 357: 266–281.

Signs and symptoms

Signs and symptoms of osteomalacia include:

  • Increased risk of fractures;
  • Fractures that happen without injury;
  • Widespread bone pain and tenderness, especially in the pelvis and lower back. Even slight pressure on bone can cause considerable pain;
  • Difficulty in walking, walking with a waddle, and;
  • Muscle weakness.

Fractures

A complete or incomplete break in a bone.

Pelvis

The bony structure in the lower part of the body trunk that connects the base of the spine to the legs. The pelvis protects important organs, such as the bladder and bowel (and in women, the uterus), and anchors thigh and abdominal muscles.

1. Holick, M.F. (2007). Vitamin D Deficiency. New England Journal of Medicine 357: 266–281.

Methods for diagnosis

Your doctor will diagnose osteomalacia based on your symptoms and the results of tests, including:

Blood tests

During a blood test, blood can be drawn using a needle or by a finger prick. Your blood can then be analysed to help diagnose and monitor a wide range of health conditions.

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

X-rays

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Bone density

Also known as bone mineral density, it is a measure of bone strength calculated as the mineral content per square centimetre of bone. The higher the mineral content, the denser and stronger the bones.

1. Holick, M.F. (2007). Vitamin D Deficiency. New England Journal of Medicine 357: 266–281.

Types of treatment

Treatment of osteomalacia focuses on you getting enough vitamin D, calcium and phosphorus in your diet and getting regular sunlight exposure. Your doctor may advise you to add certain vitamin-rich or calcium-rich foods to your diet, or to begin taking nutritional supplements.

Dietary vitamin D

Good sources of dietary vitamin D include:

  • Fish - including salmon, snapper, whitefish, mackerel, trout and herring;
  • Whole milk, butter and margarine;
  • Ricotta cheese;
  • Egg yolks;
  • Some types of mushrooms, such as shiitake mushrooms;
  • Tofu, and;
  • Foods fortified with vitamin D. These can include juices, yogurt, cereals, soy milk, almond milk and many others. Check the labelling of the package for vitamin D levels.

Exposure to sunlight

Your body needs some exposure to sunlight in order to make vitamin D. The ultraviolet radiation in sunlight (specifically UVB) activates the vitamin.

However, UVB exposure puts you at risk of skin cancer. Striking the right balance between underexposure and overexposure is not always easy. Note that your body needs only a few minutes daily of direct sunlight - in the morning or afternoon - in order to make active vitamin D.

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

Ultraviolet radiation

A type of invisible radiation found in sunlight. Ultraviolet radiation has both beneficial and harmful effects on the body. Exposure to it is a major risk factor for sunburn and skin cancer.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Phosphorus

An important mineral that is necessary for growth, formation of bones and teeth and energy metabolism.

1. Holick, M.F. (2007). Vitamin D Deficiency. New England Journal of Medicine 357: 266–281.

Prognosis

If vitamin D levels return to normal, osteomalacia should go away within a few weeks to months.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

1. Holick, M.F. (2007). Vitamin D Deficiency. New England Journal of Medicine 357: 266–281.

Prevention

Unless there is an underlying medical condition, osteomalacia can be prevented by including enough vitamin D in your diet and getting enough sunlight.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

1. Holick, M.F. (2007). Vitamin D Deficiency. New England Journal of Medicine 357: 266–281.