Vitamin D deficiency in adults: How the symptoms, risks differ in men and women

Vitamin D is crucial for keeping bones healthy and strong. In adults, being low on vitamin D can lead to soft, weak bones, a condition called osteomalacia. You might feel:

Bone pain (yes, that dull ache in your legs, hips, or lower back)
Muscle weakness or general aches
Feeling more tired or weak than usual

More extreme or long-term deficiency increases your risk for osteoporosis (thinning bones) and fractures. Sometimes the symptoms may not be obvious, which is why people can go years without realizing they’re deficient. Providers often check for deficiency if you have unexplained bone pain, muscle aches, or frequent fractures, especially if you’re not getting enough sun or have dietary limitations.

The actual symptoms, like bone pain, muscle weakness, or increased fracture risk, don’t dramatically change based on gender. Both men and women will experience similar physical effects because vitamin D affects bones and muscles the same way in everyone.

However, the risk and prevalence of deficiency can be different for men and women, and some related health risks can hit women harder.

According to the Centers for Disease Control and Prevention, the prevalence at risk of vitamin D deficiency in the U.S. (2001–2006 data) was roughly: (check the govt data on vitamin D deficiency here)

1%–8% for males
1%–12% for females

Women, especially as they get older, are at a slightly greater risk of deficiency compared to men, and risk increases even more after menopause. The CDC also found roughly one-quarter of adults were at risk for inadequacy (not full deficiency, but still sub-optimal levels) during these years.

Women: Lower vitamin D levels can contribute to osteoporosis and fractures, already a bigger problem for postmenopausal women due to lower estrogen. Pregnancy, breastfeeding, use of sunscreen, cultural clothing, or certain diets (like veganism) can further reduce vitamin D levels.

Men: Generally, men have lower risk, but some surveys report younger adult males are more likely to be deficient than older men. Lifestyle choices (like less fortified milk or supplement intake, higher soda consumption, or central obesity) are risk factors.

Osteoporosis and Osteomalacia: Vitamin D is essential for calcium absorption, key for maintaining bone strength. In women, especially postmenopausal, the risk of osteoporosis is notably higher due to both lower estrogen and a greater prevalence of vitamin D deficiency. Osteomalacia (softening of bones in adults) is another consequence, often seen when deficiency is severe.

Increased Fracture Risk: Postmenopausal and older women are at elevated risk for fractures as bone mineral density declines. The NIH and CDC note that more than 53 million U.S. adults are at risk for osteoporosis, and women make up a substantial portion of this group. Studies show that vitamin D and calcium supplements may offer a small increase in bone density for postmenopausal women.

Bone Loss After Menopause: As women age and especially after menopause, bone breakdown exceeds bone building. Without enough vitamin D, this bone loss accelerates, increasing the odds of fractures, especially at the hip and spine. Women with low vitamin D may lose bone mineral density faster than men of equivalent age.

Muscle Weakness and Pain: Women with vitamin D deficiency frequently experience muscle weakness and aches, sometimes severe enough to cause difficulty in daily activities, like rising from a chair or climbing stairs. This issue is attributed to vitamin D's role in normal muscle fiber development and function.

Falls in Older Women: Insufficient vitamin D can contribute to muscle weakness, affecting balance and increasing the risk of falls among older women. While large studies have shown mixed evidence for vitamin D supplements directly reducing fall risk, the link between deficiency and muscle impairment is clear, particularly in the frail elderly.

Myopathy and Cramps: Myopathy (muscle disease), characterized by muscle pain, cramps, and weakness, is frequently associated with severe vitamin D deficiency in women of all ages, though it is most clinically significant in older women.

Women can reduce their risk of vitamin D deficiency through a combination of sunlight exposure, diet, and supplementation. Spending 10–30 minutes in the sun a few times a week—without sunscreen on small areas like the arms or legs—helps the body naturally produce vitamin D. However, in regions like the US, UK, and Canada, sunlight may not be strong enough in the winter months, especially for women with darker skin tones or those who wear full-coverage clothing.

Diet also plays a key role. Women should include vitamin D-rich foods such as fatty fish (salmon, mackerel), egg yolks, fortified dairy or plant-based milk, and cereals. For those following vegan or dairy-free diets, fortified plant-based products and mushrooms exposed to UV light are helpful.

Supplementation is often recommended, especially for women over 50 or postmenopausal women who are at greater risk of bone loss. A daily vitamin D3 supplement (as advised by a healthcare provider) can help maintain healthy levels.

Regular screenings and blood tests can catch low levels early. Prioritizing bone health through adequate calcium intake, weight-bearing exercises, and lifestyle choices also enhances vitamin D’s effectiveness. Staying informed and proactive can significantly lower deficiency risks and support long-term health.

Vitamin D deficiency can cause subtle but important health issues. Common signs include fatigue, muscle weakness, and bone pain—often felt in the lower back, hips, or legs. You may also experience mood changes, such as depression or irritability, and frequent illnesses due to a weakened immune system. Hair thinning, poor wound healing, and general aches can also occur. In severe cases, bone loss and a higher risk of fractures are concerns, especially in older adults.