Vitamin D Deficiency in Women

Why Women Are More Vulnerable

Women are generally more prone to vitamin D deficiency than men. This issue often develops early in life and becomes more pronounced with age, particularly in pregnant women. The deficiency might not show symptoms immediately, making it difficult to detect until it becomes more severe.

Symptoms of Vitamin D Deficiency in Women

A preliminary study published in Nutrients in 2018 found a link between vitamin D deficiency and irregular menstrual cycles in young women. The researchers noted that low vitamin D levels may be associated with increased menstrual disturbances, suggesting that supplementation could help regulate the cycle.

Common Symptoms of Vitamin D Deficiency

Many people experience vitamin D deficiency without noticeable symptoms. However, some may feel persistent fatigue or general body aches. Severe deficiency is easier to identify due to more obvious symptoms, such as bone deformities.

Frequent Illness

Vitamin D plays a key role in strengthening the immune system. A deficiency may weaken your body’s defenses, making you more susceptible to infections like the cold and flu.

Depression

Studies suggest a correlation between low vitamin D levels and depression, especially in older adults. A 2016 review in the Journal of Affective Disorders indicated a potential link between vitamin D deficiency and late-life depression, although more research is needed.

Hair Loss

A 2013 study in Skin Pharmacology and Physiology observed a connection between vitamin D deficiency and hair loss in women aged 18 to 45. Though the exact mechanism isn’t clear, vitamin D may play a role in the expression of genes involved in hair follicle growth. Low ferritin levels also appear to be associated with hair loss.

Excessive Sweating

While sweating is a normal bodily function, excessive sweating—especially of the head—may be an early sign of vitamin D deficiency.

Bone and Joint Pain

Vitamin D is essential for bone density. Deficiency can cause pain in bones and joints, and may also increase the risk of rheumatoid arthritis. A 2012 study in Therapeutic Advances in Endocrinology and Metabolism linked low vitamin D levels to a higher risk of this condition. Supplementation may help reduce symptoms.

Bone Fractures

Vitamin D enhances calcium absorption, helping to maintain bone strength. This is particularly important for postmenopausal women, who face a higher risk of osteoporosis and fractures.

Who Is Most at Risk?

The following groups are at a higher risk for vitamin D deficiency:

• Women, especially those who are pregnant or breastfeeding
• Older adults, due to reduced skin synthesis
• Infants, because breast milk is low in vitamin D
• People with malnutrition or who have undergone bariatric surgery
• Individuals with obesity
• Vegans, who may not get enough vitamin D from plant-based sources
• People with limited sun exposure
• Individuals with dark skin, which synthesizes less vitamin D from sunlight
• People with chronic liver or kidney disease
• Those with hyperparathyroidism or granulomatous diseases like sarcoidosis or tuberculosis

Diagnosing Vitamin D Deficiency

The most common test for vitamin D levels is the 25-hydroxyvitamin D blood test. Reference ranges are:

• Optimal: Above 75 nmol/L
• Insufficient: 50–75 nmol/L
• Deficient: 25–50 nmol/L
• Severely deficient: Below 25 nmol/L

Improving Vitamin D Levels

For mild deficiencies, doctors may recommend lifestyle changes such as:

• Increased sunlight exposure
• Eating more calcium-rich foods
• Engaging in regular physical activity
• Taking over-the-counter vitamin D supplements after medical consultation

For moderate to severe deficiencies, prescription supplements or injectable forms of vitamin D may be necessary, based on age, body mass index, and overall health.

Recommended Daily Intake for Women

The Importance of Vitamin D for Women

Vitamin D regulates calcium levels in the blood, supports bone density, and enhances calcium and phosphorus absorption in the intestines. It is also vital for immune function, bone regeneration after fractures, and cell growth in various tissues.

Sources of Vitamin D

Sunlight

Exposure to sunlight helps the skin synthesize vitamin D. Around 10 minutes of midday sun exposure, 3–4 times a week, may be sufficient in many regions. However, during certain times of the year or in northern latitudes, sunlight may not provide enough UVB rays for adequate vitamin D synthesis.

Food Sources