Vitamin D plays several crucial roles in the body. These include maintaining healthy teeth, bones, and muscles, as well as helping to regulate mood. Foods such as fish, cheese, and egg yolks are good sources of vitamin D. Your skin also produces vitamin D when you're directly exposed to the sun.

Vitamin D is essential for optimal health, yet many people simply aren't getting enough. It's estimated that over a billion people worldwide are vitamin D deficient or insufficient. Covering up from the sun and avoiding peak sunshine hours are two of the common measures that are taken to reduce the risk of skin cancer. This approach, coupled with the fact that it can be difficult to get sufficient vitamin D from dietary sources alone, are likely reasons for such widespread deficiency.

With many people spending more time indoors during the COVID pandemic it's probable that a lack of vitamin D is more prevalent than ever. Here are some of the common signs and symptoms of vitamin D deficiency to watch out for.

Mood changes

Low levels of vitamin D have been linked to depression, and some studies have suggested that supplementation with vitamin D may help to alleviate depressive symptoms.

For some people, depressive symptoms are more prevalent over the winter months. This is known as Seasonal Affective Disorder (SAD). Reduced sunlight can affect the body's circadian rhythm, as well as serotonin and melatonin levels. These factors can negatively affect mood. Reduced production of vitamin D from the sun during this time of year could also be exacerbating the problem.

It's possible that there will be multiple factors at play when it comes to the cause of depressive symptoms. A vitamin D deficiency should be explored as one possible contributor.

Bone problems

Vitamin D helps the body to absorb calcium, which means it plays an important role in keeping bones strong and healthy. An extreme deficiency of vitamin D in children can cause rickets, which occurs when the bones become soft and bendy. In adults, a severe deficiency can cause osteomalacia.

Weak and painful bones are symptoms of osteomalacia and could also be indicative of a vitamin D deficiency. Other bone-related warning signs of possible vitamin D deficiency include loss of bone mineral density, which could present as easily fractured bones, or osteoporosis.

Low bone mineral density and other bone issues could also be indicative of low levels of calcium or other minerals. However, it's worth looking at vitamin D, especially due to its close relationship with calcium.

Autoimmune diseases

Autoimmune diseases are caused by an abnormal, overactive response from the body's immune system. Instead of fighting infection, immune system antibodies can start attacking and damaging tissues in the body.

There are currently more than 80 known autoimmune diseases that affect a wide range of body parts. A few commonly-known examples include:

• Type I diabetes, which affects the ability of the pancreas to produce insulin
• Psoriasis, which causes large scaly patches on the skin that can be very itchy and painful
• Rheumatoid arthritis, which attacks joints in the body

Low vitamin D levels have been linked to several autoimmune diseases, including Multiple Sclerosis (MS) and Type I Diabetes. Low vitamin D levels have been found in people with MS; however it is unclear whether is is a contributing cause or an effect of the disease. There is a strong correlation between Type I diabetes and vitamin D. Vitamin D supplementation may even be able to reduce the risk of Type I diabetes.

Overall, autoimmune diseases can be a complex and multi-faceted issue. Some autoimmune diseases could be indicative of a vitamin D deficiency, so it's an avenue worth exploring.

Fatigue

Fatigue is a common complaint and it could be indicative of any number of problems or conditions. Sometimes, the cause of fatigue is easily identified. Common causes include poor nutrition intake, sleep deprivation, over-working, or chronically high stress levels. At other times, it's harder to determine what underlying issue is causing a person to feel fatigued.

Vitamin D deficiency is one possible cause of fatigue that is regularly overlooked. In a study of 174 patients who presented with fatigue, 77% were found to have low vitamin D levels. When vitamin D levels were normalized, fatigue symptom scores improved significantly.

When the cause of fatigue cannot be easily identified, vitamin D status could be assessed to determine whether it may be the cause, or a contributing factor.

Muscle weakness, pain, or cramps

Muscle weakness, pain, or cramps could be signs and symptoms a vitamin D deficiency. Muscle pain and weakness has been reported in both children and adults with vitamin D deficiency. These symptoms could also present alongside symptoms of bone pain and weakness.

Slow healing wounds

There is some evidence that vitamin D status is linked to wound prevalence and healing. This could be due to the anti-inflammatory properties of vitamin D.

One study found that patients with leg ulcers had greater vitamin D deficiencies and that vitamin D assisted with healing. The results from another study suggested that Vitamin D supplementation played a role in wound healing in patients with a diabetic foot ulcer.

Therefore, when wound healing is impaired, vitamin D status can be tested as a possible cause or contributing factor.

In Conclusion

There are several potential indicators of a vitamin D deficiency. These include depressive symptoms, bone and muscle problems and conditions, fatigue, and autoimmune diseases.

These signs and symptoms could present in isolation, or as a combination that is not limited to those listed above.

It's important to recognize that the signs and symptoms discussed above could also be indicative of a completely different problem. The best way to find out whether you have a vitamin D deficiency is by taking a blood test, which can be arranged through your doctor.