Vitamin D is an extremely important vitamin that has powerful effects on several systems throughout your body (1Trusted Source).
Unlike other vitamins, vitamin D functions like a hormone, and every single cell in your body has a receptor for it.
Your body makes it from cholesterol when your skin is exposed to sunlight.
Here are common risk factors for vitamin D deficiency:
- Having dark skin.
- Being elderly.
- Being overweight or obese.
- Not eating much fish or dairy.
- Living far from the equator where there is little sun year-round.
- Always using sunscreen when going out.
- Staying indoors.
People who live near the equator and get frequent sun exposure are less likely to be deficient, as their skin produces enough vitamin D to satisfy their bodies’ needs.
Most people don’t realize that they’re deficient, as symptoms are generally subtle. You may not recognize them easily, even if they’re having a significant negative effect on your quality of life.
Here are signs and symptoms of vitamin D deficiency.
1. Getting Sick or Infected Often
One of vitamin D’s most important roles is keeping your immune system strong so you’re able to fight off viruses and bacteria that cause illness.
It directly interacts with the cells that are responsible for fighting infection (4Trusted Source).
If you often become sick, especially with colds or the flu, low vitamin D levels may be a contributing factor.
Several large observational studies have shown a link between a deficiency and respiratory tract infections like colds, bronchitis and pneumonia (5Trusted Source, 6Trusted Source).
2. Fatigue and Tiredness
Feeling tired can have many causes, and vitamin D deficiency may be one of them.
Unfortunately, it’s often overlooked as a potential cause.
Case studies have shown that very low blood levels can cause fatigue that has a severe negative effect on quality of life (11Trusted Source, 12Trusted Source).
3. Bone and Back Pain
Vitamin D helps maintain bone health in a number of ways.
For one, it improves your body’s absorption of calcium.
Bone pain and lower back pain may be signs of inadequate vitamin D levels in the blood.
A depressed mood may also be a sign of vitamin D deficiency.
In review studies, researchers have linked vitamin D deficiency to depression, particularly in older adults (19Trusted Source, 20Trusted Source).
In one analysis, 65% of the observational studies found a relationship between low blood levels and depression.
.5. Impaired Wound Healing
Slow healing of wounds after surgery or injury may be a sign that your vitamin D levels are too low.
Results from a test-tube study suggest that the vitamin increases the production of compounds that are crucial for forming new skin as part of the wound-healing process (23Trusted Source).
One analysis looked at patients with diabetic foot infections
It found that those with severe vitamin D deficiency were more likely to have higher levels of inflammatory markers that can jeopardize healing (25Trusted Source).
6. Bone Loss
Vitamin D plays a crucial role in calcium absorption and bone metabolism.
Many older people who are diagnosed with bone loss believe they need to take more calcium. However, they may be deficient in vitamin D as well.
Low bone mineral density is an indication that your bones have lost calcium and other minerals. This places older adults, especially women, at an increased risk of fractures.
However, a controlled study found that women who were vitamin D deficient experienced no improvement in bone mineral density when they took high-dose supplements, even if their blood levels improved (28Trusted Source).