Vitamin D Deficiency: Causes, Symptoms & Treatment

What is vitamin D deficiency?

Vitamin D deficiency means you don’t have enough vitamin D in your body. It primarily causes issues with your bones and muscles.

Vitamin D is an essential vitamin that your body uses for normal bone development and maintenance. Vitamin D also plays a role in your nervous system, musculoskeletal system and immune system.

You can get vitamin D in a variety of ways, including:

• Sun exposure on your skin (however, people with darker skin and older people may not get enough vitamin D through sunlight. Your geographical location may also prevent adequate vitamin D exposure through sunlight).
• Through the food you eat.
• Through nutritional supplements.

Despite all these methods to get vitamin D, vitamin D deficiency is a common worldwide problem.

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Why is vitamin D so important?

Vitamin D is one of many vitamins your body needs to stay healthy. It plays a crucial role in maintaining the balance of calcium in your blood and bones and in building and maintaining bones.

More specifically, you need vitamin D so your body can use calcium and phosphorus to build bones and support healthy tissues.

With chronic and/or severe vitamin D deficiency, a decline in calcium and phosphorus absorption by your intestines leads to hypocalcemia (low calcium levels in your blood). This leads to secondary hyperparathyroidism (overactive parathyroid glands attempting to keep blood calcium levels normal).

Both hypocalcemia and hyperparathyroidism, if severe, can cause symptoms, including muscle weakness and cramps, fatigue and depression.

To try to balance calcium levels in your blood (via secondary hyperparathyroidism), your body takes calcium from your bones, which leads to accelerated bone demineralization (when a bone breaks down faster than it can reform).

This can further result in osteomalacia (soft bones) in adults and rickets in children.

Osteomalacia and osteoporosis put you at an increased risk for bone fractures. Rickets is the same as osteomalacia, but it only affects children. Since a child’s bones are still growing, demineralization causes bowed or bent bones.

Who does vitamin D deficiency affect?

Anyone can have vitamin D deficiency, including infants, children and adults.

Vitamin D deficiency may be more common in people with higher skin melanin content (darker skin) and who wear clothing with extensive skin coverage, particularly in Middle Eastern countries.

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How common is vitamin D deficiency?

Vitamin D deficiency is a common global issue. About 1 billion people worldwide have vitamin D deficiency, while 50% of the population has vitamin D insufficiency.

Approximately 35% of adults in the United States have vitamin D deficiency.