5 Signs You Might Have a Vitamin D Deficiency

Though magical at times, winter does have its flaws. The days are darker (and obviously more frigid), and we spend less time outdoors, which leads to many of us experiencing a common—but very serious—health condition: a vitamin D deficiency. Research shows that one billion people around the world are vitamin D deficient, a reality that has major health ramifications.

From bone pain to medical conditions, low vitamin D is a problem worth tending to ASAP. The good news? There are a few easy ways to keep those levels in check. Below, the experts break down everything you need to know about vitamin D along with their best advice for getting enough vitamin D.

Why is vitamin D good for the body?Vitamin D, as Jenna Stangland, MS, RD, registered dietician and performance advisor for Momentous, explains it, is a hormone that our body can synthesize from UV light. Stangland says it has numerous functions in our body and comes with many benefits. Optimal vitamin D levels are essential for systemic health.

“It regulates cellular growth and gene expression (essential for cancer prevention), improves cell differentiation, and is involved in immunity, fertility, muscle strength, hormone balance, sexual health, energy, mood, and more,” adds Rhian Stephenson, nutritionist, naturopath, and founder of Artah. Put simply, it’s essential for all-around health and well-being. 

What happens if you’re vitamin D deficient?Vitamin D deficiency impacts both physical and mental health. When vitamin D is low, Stangland explains that there is decreased absorption of calcium and phosphorus into the bones, which puts you at risk of bone fractures. 

Low levels are also linked to poor immunity and increased risk of serious health conditions such as cancer. “Vitamin D has been shown to play a role in cancer prevention and treatment,” she explains. “[It] inhibits cell proliferation in cancerous tissues and also downregulates certain cells involved in inflammatory signaling in cancer.” Other poor outcomes include autoimmune conditions, COVID-19, hormone health, and mood disorders, Stephenson. Hypertension, diabetes, chronic kidney disease, liver disease, fibromyalgia, and neurological disorders, such as multiple sclerosis, are all also linked to vitamin D deficiency. 

Those who eat a vegan diet or who have celiac disease, Crohn’s disease, and cystic fibrosis are particularly at risk of vitamin D deficiency. Others who are at risk are babies who are breastfed, older adults, those with dark skin tones, and those who weigh above their standard body mass index (BMI). According to the National Institutes of Health (NIH), breast milk’s vitamin D levels are lower than the required amounts and also dependent on the mother’s vitamin D levels. When it comes to older people or those with darker skin tones, the NIH explains that our skin has a harder time synthesizing vitamin D as we age or if we have melanin in the epidermal layer that reduces the skin’s ability to do so. Those who may be dealing with excess fat won’t necessarily have a problem absorbing vitamin D, but the NIH says that they will need more of it to be sufficient.

What are the symptoms of vitamin D deficiency?The only way to truly know if you are vitamin D deficient is to have a blood test via your general practitioner. However, there are also signs and symptoms you can look out for. 

Fatigue

When you have a severe vitamin D deficiency, one of the most common symptoms is a feeling of chronic, profound, or irremediable fatigue. To add to that, poor sleep is another symptom. 

Bone and Muscle Pain

Some studies have shown a correlation between vitamin D deficiency and frequent muscle pain and weakness. Meanwhile, bone and joint pain are common, as vitamin D is essential for the body to absorb calcium—without it, increased fragility and pain may occur. So for the sake of your bone health, vitamin D is key.

Hair Loss

It’s essential for healthy hair that grows optimally. A deficiency can cause hair to fall out or slow growth because a deficiency intervenes with a follicle’s life cycle. Alopecia is also believed to be related to vitamin D insufficiency. 

You’re Often Sick

Vitamin D deficiency is associated with a weak immune system. If you’re often ill and don’t know why, consider getting a blood test. 

Depression, Anxiety, and Mood Disorders

Scientific research shows that vitamin D may play a key role in balancing our mood and minimizing the risk of depression. Low levels can contribute to seasonal affective disorder and are often associated with feelings of overwhelm, sadness, anxiety, forgetfulness, and sadness.

How do you get vitamin D? It is well known that sunlight exposure is the easiest way to stimulate the production of vitamin D in the body, which is why we’re particularly vulnerable to deficiency in the dark winter months. “The NHS recommends supplementing with vitamin D3 throughout autumn and the winter months for this reason,” explains Stephenson. Stangland recommends getting at least 20 minutes of sun exposure to keep vitamin D levels at a healthy amount. (Just be sure to always wear sunscreen to protect your skin from sun damage and to prevent skin cancer.)