14 Low Vitamin D Symptoms - Health.com

Vitamin D deficiency occurs when your body doesn't get or process adequate amounts of vitamin D. Vitamin D helps your body absorb calcium, so a deficiency can lead to osteoporosis (low bone density) and fractures (broken bones). Other low vitamin D symptoms include muscle weakness and cramps, hair loss, and tiredness or fatigue.

Most people have the vitamin D that their body needs, but as many as one in four adults in the United States are deficient. This is partly because vitamin D isn't quite as easy to get naturally as some other nutrients. Your body makes some vitamin D when you are in the sun, and you can also find it in foods like fish, egg yolks, and fortified foods—as well as in supplement form.

Vitamin D deficiency can be hard to diagnose because it either produces no symptoms or its symptoms overlap with many health conditions. The good news: a vitamin D deficiency is relatively easy to treat with supplements once your healthcare provider identifies that you're deficient.

It's unclear exactly why low vitamin D levels might make you feel tired or lead to fatigue, but multiple studies have shown that people who take vitamin D supplements report an improvement in fatigue and an increase in overall energy levels.

Vitamin D bolsters the immune system. If you're constantly getting sick—or becoming seriously ill with even minor infections—a deficiency could be to blame. In fact, some research has found a link between higher disease severity in people in intensive care units (ICUs) and low levels of vitamin D. This was examined again after the onset of COVID-19. Studies showed that people with deficiencies may have had a higher risk of getting COVID and getting sicker from the virus.

Vitamin D promotes muscle function. Low vitamin D levels may increase the likelihood of experiencing symptoms such as loss of muscle tone, atrophy (muscle loss), weakness, and pain. Losing muscle mass and strength can also make you more prone to falling.

The loss of muscle strength can lead to increased stress on your back and neck muscles, which can lead to back pain.

Lower back pain in particular is a common complaint among people with vitamin D deficiencies. Some experts suggest screening people with lower back pain for vitamin D deficiencies may be helpful, as treatment such as vitamin D supplements, can ease pain-related symptoms.

Our bodies rely on vitamin D to help absorb calcium and grow bones that stay dense and strong throughout our lives. A deficiency can cause osteomalacia in adults, a condition that leads to the softening of the bones.

This can lead to a loss of bone density, which can contribute to osteoporosis and fractures (broken bones). Approximately 50% of women over the age of 50 will break a bone because of osteoporosis.

The risk of osteoporosis increases with age. The National Osteoporosis Foundation recommends an intake of 400-800 international units (IU) of vitamin D per day for adults under the age of 50 and 800-1,000 IU for those over the age of 50.

Vitamin D plays an important part in regulating the hair cycle, including the regeneration of new hair. That said, it's possible that a deficiency could slow hair growth.

Alopecia is an autoimmune disorder that causes hair loss. People with alopecia have lower levels of vitamin D, and topical vitamin D treatments have been used to improve symptoms.

The research is mixed on whether taking vitamin D supplements can improve existing symptoms of depression, but multiple studies and reviews have shown that people with a vitamin D deficiency may be at an increased risk of experiencing depressive episodes.

Low vitamin D can cause weight gain. People with obesity (excess fat cells) are 35% more likely to be vitamin D deficient than people without obesity. They're also 24% more likely to be D deficient than people who are considered overweight.

Healthcare providers diagnose obesity using a tool called the body mass index (BMI). BMI is an imperfect tool because it's solely based on your height and weight. Providers may also consider your waist circumference (the measurement around your waist). Research suggests that a larger amount of adipose tissue (body fat) around your abdomen may increase your risk of chronic health conditions like heart disease and diabetes, a chronic disease that occurs when you have higher than normal levels of blood glucose (blood sugar).

The accumulation of vitamin D in adipose tissue might explain why people with obesity have low vitamin D blood levels. Fat cells hold on to vitamins and don't release them into the blood efficiently.

Vitamin D is known to affect the immune system and skin barrier function, both critical in the development of eczema. Eczema is a group of chronic skin conditions that can cause skin inflammation, irritation, and swelling.

Lower blood serum vitamin D levels have been associated with increased frequency and severity of eczema symptoms. Supplementing with vitamin D in pill form might improve winter-related eczema.

Vitamin D is crucial to dental health, including the formation of teeth during infancy and childhood—yet another reason why taking prenatal vitamins is so important.

One study measured the blood levels of vitamin D in pregnant people, then checked the teeth of their babies at one year. Researchers found that parents of children with weak enamel and tooth decay had significantly lower vitamin D levels during pregnancy compared to parents of children with healthy teeth.

Vitamin D is essential for healthy teeth and gums because it helps your body absorb calcium. Low vitamin D can weaken your teeth and make you more susceptible to cavities, fractures, and decay.

It's also linked with an increased risk of periodontitis, possibly because of its connection to the immune system. Periodontitis is a gum disease that causes gum inflammation. Vitamin D seems to reduce inflammation and mineralization effects on the tissue surrounding your teeth.

Vitamin D helps prevent infection by helping your body produce natural antibiotics. Vitamin D deficiency might be a risk factor for urinary tract infections (UTIs), especially those assigned female at birth.

UTIs are bacterial infections that affect any part of the urinary system— including the bladder, kidneys, ureters, and urethra. Research has found that people with recurrent UTIs might have lower levels of vitamin D.

Vitamin D is critical for muscle strength. A deficiency can contribute to weakness in the pelvic floor—the hammock of muscles that supports your bladder, vagina, uterus, and rectum. One 2019 meta-analysis found that vitamin D levels in people with pelvic floor disorder (PFD) were significantly lower than levels in people without PFD.

PFD includes urinary incontinence and fecal incontinence as well as pelvic organ prolapse—when pelvic muscles weaken and fall lower in the pelvis, sometimes bulging into the vagina. More research is needed to determine possible connections between vitamin D and these conditions.

Rickets is the softening and weakening of bones in children. It can be inherited from a parent or related to a prolonged vitamin D deficiency (nutritional rickets).

Children who are 3-36 months old are at the highest risk because their bones grow rapidly. In the late 19th century, doctors realized that vitamin-D-rich cod liver oil helped to prevent and treat rickets in children. Manufacturers added vitamin D to milk for the first time in the 1930s, and rickets has since become rare in the U.S.

When nutritional rickets is diagnosed, supplementation with calcium and vitamin D corrects most bone damage within a few months, sometimes within a few days. The American Academy of Pediatrics recommends that all infants, children, and adolescents receive a minimum daily intake of 400 IU of vitamin D.

Contact a healthcare provider if you or your child has symptoms of bone or hair loss, muscle pain, or fatigue, or are frequently becoming ill or experiencing bone fractures with no clear cause. A provider can assess your symptoms and order diagnostic tests (such as bloodwork) to check your vitamin D levels, as well as other nutrient levels. If your results show that you have a vitamin D deficiency, your provider can recommend the correct dosage of vitamin D supplementation.

Always consult with a healthcare provider before trying supplements. Dietary supplements are minimally regulated by the FDA and may or may not be suitable for you. The effects of supplements vary from person to person and depend on many variables, including type, dosage, frequency of use, and interactions with current medications. Too much vitamin D from supplements can have adverse side effects.

Vitamin D is a vital nutrient that offers numerous essential benefits for your bones, muscles, nerves, and immune system. Too little vitamin D can lead to symptoms like fatigue, frequent illness or bone fractures, hair loss, and muscle and bone pain. In children, severe deficiency can cause rickets and tooth decay.

A blood test can confirm if you have a vitamin D deficiency. If you have a deficiency, your healthcare provider can guide you in safely increasing your levels with vitamin D supplementation.