These Are The Signs Your Body Might Be Begging You For More Vitamin D (Mine Certainly Was)

“When vitamin D levels are low, the skeletal system, muscles, and immune response are most commonly affected," Natividad-Li said. "It helps the body absorb calcium and phosphorus, which are essential for maintaining strong bones and teeth." Without enough vitamin D, that absorption becomes less efficient, which can gradually reduce bone density.

Over time, this can increase the risk of osteoporosis and fractures. Because the process is slow, many people don’t realize there’s a problem until much later in life.

Ever feel exhausted even after a full night of sleep? Vitamin D could be playing a role. “Low vitamin D can present as fatigue, muscle weakness or aches, and bone or joint pain,” Natividad-Li said. 

This happens because vitamin D supports normal muscle function. When levels drop, muscles may not perform as efficiently, and that can make everyday movement feel harder than it should.

Along with fatigue, muscle aches and joint pain are common signs of a deficiency. "These symptoms occur because calcium absorption becomes less efficient," Natividad-Li said. This directly affects the skeletal and muscular systems.

So, if you’ve been blaming your sore body on aging, stress, or “sleeping weird,” same — but also, vitamin D might be involved.

Vitamin D also plays a role in immune health. According to Natividad, low levels may lead to more frequent infections because immune function can become impaired.

If it feels like you’re constantly getting sick or taking longer than usual to recover, vitamin D deficiency could be one piece of the puzzle.

Vitamin D doesn’t just affect bones and muscles. It also plays a role in hair follicle cycling, so low levels may be associated with increased hair shedding or thinning. Especially when levels remain low over time.

In other words: Put down that hat, king. And pick up some vitamin D. 

Vitamin D deficiency isn’t just coming for you physically. It could also be affecting you mentally. Vitamin D interacts with neurotransmitters in the brain, which may explain why deficiency has been associated with symptoms of depression and anxiety.

These effects aren’t always dramatic, but people may notice persistent low mood, irritability, or a general sense of emotional flatness when vitamin D levels are low, low, low, low, low, low (like baaaaaggy sweatpants).

Vitamin D supports skin cell growth and repair, which means deficiency can sometimes show up on the skin. Studies show that low vitamin D levels may be linked to dullness, dryness, faster-aging skin, and slower healing of minor wounds.

Skin changes alone don’t confirm a deficiency, but look out for it as another subtle sign, when combined with other symptoms, that you might need more D in your life.

From a nutrition standpoint, the long-term consequences of low vitamin D aren’t always obvious early on. “Over time, inadequate vitamin D increases the risk of low bone density, osteoporosis, and fractures,” Natividad-Li said.

She also said that reduced muscle strength may increase the risk of falls as people age, making deficiency especially concerning over the long term.

Many people assume they’re getting enough vitamin D from being outside, but that’s not always true. For example, “for most Canadians, sunlight is not a reliable source of vitamin D during the winter,” Natividad said.

From roughly October through April, the sun’s UVB rays are too weak to stimulate vitamin D production in the skin, which makes dietary sources and supplementation especially important during that time. 

But even if you do get sun year-round, it might still not be enough vitamin D for you.

“People with darker skin tones produce less vitamin D from sunlight,” Natividad says. "And those who live in northern regions or work indoors may also have limited year-round sun exposure." Also at risk are people who cover their skin for weather or religious reasons.

And diet plays a role, too. "People following vegan or highly restrictive diets may miss common sources like fatty fish, eggs, and fortified dairy," Natividad said. "These groups should prioritize vitamin D–rich foods daily and consider a consistent winter supplement to help maintain adequate levels."

For people who'd rather not rely on supplements, vitamin D can still be built into daily meals. "Vitamin D can be obtained through foods such as fatty fish, egg yolks, and fortified milk or plant-based beverages."

And because vitamin D is fat-soluble, she notes that absorption improves when these foods are eaten with meals that include healthy fats.

When supplements are necessary, Natividad recommends vitamin D3, also known as cholecalciferol, because it’s more effective at maintaining blood levels.

“Because vitamin D is fat-soluble, supplements should be taken with a meal that contains fat,” she said. "Common mistakes include taking supplements on an empty stomach or using doses that are too low," especially during the winter months.

At the very least, it’s made me realize I should probably stop assuming my body is “fine” without checking in.