- 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. If you often become sick, especially with colds or the flu, low vitamin D levels may be a contributing factor.
- Fatigue and tiredness
A large observational study looked at the relationship between vitamin D and fatigue in young women. The study found that women with blood levels lower than 20 ng/ml or 21–29 ng/ml were more likely to complain of fatigue than those with blood levels over 30 ng/ml. Another observational study in female nurses found a strong connection between low vitamin D levels and self-reported fatigue. What’s more, the researchers found that 89% of the nurses were deficient.
- Bone and back pain
Bone pain and lower back pain may be signs of inadequate vitamin D levels in the blood. Large observational studies have found a relationship between deficiency and chronic lower back pain. One study examined the association between vitamin D levels and back pain in more than 9,000 older women. The researchers found that those with a deficiency were more likely to have back pain, including severe back pain that limited their daily activities.
- Depression
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. In one analysis, 65% of the observational studies found a relationship between low blood levels and depression. On the other hand, most of the controlled trials, which carry more scientific weight than observational studies, didn’t show a link between the two. However, the researchers who analyzed the studies noted that the of vitamin D in controlled studies were often very low.
- 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. One study on people who had dental surgery found that certain aspects of healing were compromised by vitamin D deficiency. It’s also been suggested that vitamin D’s role in controlling inflammation and fighting infection is important for proper healing.
- 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. In a large observational study in more than 1,100 middle-aged women in menopause or postmenopause, researchers found a strong link between low vitamin D levels and low bone mineral density.
- Hair loss
Hair loss is often attributed to stress, which is certainly a common cause. However, when hair loss is severe, it may be the result of a disease or nutrient deficiency. Hair loss in women has been linked to low vitamin D levels, though there is very little research on this to date. Alopecia areata is an autoimmune disease characterized by severe hair loss from the head and other parts of the body. It’s associated with rickets, which is a disease that causes soft bones in children due to vitamin D deficiency. Low vitamin D levels are linked to alopecia areata and may be a risk factor for developing the disease.
- Muscle pain
The causes of muscle pain are often difficult to pinpoint. There is some evidence that vitamin D deficiency may be a potential cause of muscle pain in children and adults. In one study, 71% of people with chronic pain were found to be deficient. The vitamin D receptor is present in nerve cells called nociceptors, which sense pain. One study in rats showed that a deficiency led to pain and sensitivity due to the stimulation of nociceptors in muscles. A few studies have found that taking high-dose vitamin D supplements may reduce various types of pain in people who are deficient.