Vitamin D Deficiency : Symptoms and causes

Vitamin D deficiency is a common vitamin deficiency that causes issues with your bones and muscles.

Vitamin D deficiency is a common vitamin deficiency that causes issues with your bones and muscles. It most commonly affects people over the age of 65 and people who have darker skin. It’s preventable and treatable.

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.


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.
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.
Symptoms and Causes
Signs of vitamin D deficiency in adults may not be obvious, but they include muscle cramps, mood changes fatigue and more.
Anyone can have vitamin D deficiency, including infants, children and adults.
What are the signs and symptoms of vitamin D deficiency?

Severe lack of vitamin D in children causes rickets. Symptoms of rickets include:

    Incorrect growth patterns due to bowed or bent bones.
    Muscle weakness.
    Bone pain.
    Deformities in joints.

This is very rare. Children with a mild vitamin deficiency may just have weak, sore and/or painful muscles.
Lack of vitamin D isn’t quite as obvious in adults. Signs and symptoms might include:
However, you may have no signs or symptoms of vitamin D deficiency.
What causes vitamin D deficiency?
In general, the two main causes of vitamin D deficiency are:
There are several specific causes of vitamin D deficiency, including:
Weight-loss surgeries that reduce the size of your stomach and/or bypass part of your small intestines, such as gastric bypass surgery, make it difficult for your body to absorb sufficient quantities of certain nutrients, vitamins and minerals.
If you’ve had weight-loss surgery, it’s important to see your healthcare provider regularly so they can monitor your vitamin D levels and other nutrient levels. You’ll likely need to take vitamin D supplements and other supplements throughout your life.
Medications that can cause vitamin D deficiency
Certain medications can lower vitamin D levels, including:

How is vitamin D deficiency diagnosed?

Healthcare providers don’t usually order routine checks of vitamin D levels, but they might need to check your levels if you have certain medical conditions or risk factors for vitamin D deficiency and/or have symptoms of it.
Your provider can order a blood test to measure your levels of vitamin D. There are two types of tests that they might order, but the most common is the 25-hydroxyvitamin D, known as 25(OH)D for short.

How is vitamin D deficiency treated?
The goals of treatment and prevention for vitamin D deficiency are the same: to reach and then maintain an adequate vitamin D level in your body.
While you might consider eating more foods containing vitamin D and getting more sunlight, your healthcare provider will likely recommend taking vitamin D supplements.
Vitamin D comes in two forms: D2 and D3. D2 (ergocalciferol) comes from plants. D3 (cholecalciferol) comes from animals. You need a prescription to get D2. D3, however, is available over the counter. Your body more easily absorbs D3 than D2.


Who is most at risk for vitamin D deficiency?

Aside from medical conditions that can lead to vitamin D deficiency, biological and environmental factors that put someone at an increased risk of vitamin D deficiency include:
How can I prevent vitamin D deficiency?
The best way to prevent vitamin D deficiency is to ensure you’re getting enough vitamin D in your diet and/or through sun exposure. But be careful about being in the sun for too long without sunscreen. Excessive sun exposure puts you at an increased risk for skin cancer.
The amount of vitamin D you need each day depends on your age. The average daily recommended amounts are listed below in micrograms (mcg) and International Units (IU).



There are a few foods that naturally have some vitamin D, including:

    Fatty fish such as salmon, tuna and mackerel and sardines.
    Rainbow trout.
    Beef (cow) liver.
    Mushrooms.
    Egg yolks.
    Cod liver oil.

You can also get vitamin D from fortified foods. Be sure to check the nutrition labels to find out if a food has vitamin D. Foods that often have added vitamin D include:

    Cow’s milk and soy, almond and oat milk.
    Breakfast cereals.
    Orange juice.
    Other dairy products, such as yogurt.