Primarily recognized for enhancing calcium absorption, vitamin D plays a role in maintaining bone and dental health, supporting the immune system, regulating cell growth, influencing mood, and preventing conditions such as multiple sclerosis.

What Are the Signs and Symptoms of Vitamin D Deficiency?

Vitamin D deficiency is the most prevalent nutritional deficiency, affecting people of all ages globally. In the United States, nearly one-quarter of individuals have insufficient or deficient vitamin D blood levels, which can impact bone and overall health. Approximately 50 percent of children between ages 1 and 5 and 70 percent aged 6 to 11 experience vitamin D deficiency.

Vitamin D deficiency often arises due to insufficient sunlight exposure, inadequate dietary intake, and the skin's inability to produce it. Also, natural foods typically do not provide enough vitamin D to prevent deficiency, making sunlight exposure a crucial factor.

Most people with vitamin D deficiency experience no symptoms. For others, common symptoms may include:

Fatigue: Vitamin D deficiency has been linked to fatigue in uncontrolled trials, and treatment with the vitamin has been shown to improve the condition in blinded, randomized, placebo-controlled trials. Individuals with persistent and severe vitamin D deficiency may encounter symptoms linked to secondary hyperparathyroidism, including fatigue. Secondary hyperparathyroidism is when the parathyroid excretes too much hormone due to low calcium levels.

Bone and muscle pain: A mild but prolonged vitamin D deficiency can result in chronic hypocalcemia (low calcium) and hyperparathyroidism, with symptoms such as bone pain and muscle aches.