Why Vitamin D Levels Are Low in Many Women

If you’ve been feeling unusually tired, dealing with frequent aches, or worrying about bone health, vitamin D might not be the first thing that comes to mind but it should be. Vitamin D deficiency is surprisingly common, and research suggests women are more likely than men to have low levels.

We spoke with a clinical pharmacy expert to better understand why vitamin D deficiency affects so many women and what you can do about it.

Why Women Are More Prone to Vitamin D Deficiency

Vitamin D plays a critical role in helping your body absorb calcium, which supports strong bones and teeth. Without enough vitamin D, bone density can decline, increasing the risk of osteoporosis and fractures.

So why are women more susceptible?

1. Hormonal Changes and Estrogen Levels

Estrogen plays an important role in vitamin D metabolism. It helps activate the enzyme that converts vitamin D into its usable form in the body.

During menopause and postmenopause, estrogen levels decline significantly. This drop can:

• Reduce vitamin D activation

• Lower calcium absorption

• Accelerate bone loss

Women lose bone mass more rapidly after menopause, making adequate vitamin D even more important. In fact, osteoporosis affects women at nearly twice the rate of men, according to global health data.

2. Pregnancy and Breastfeeding

Vitamin D needs can increase during pregnancy and breastfeeding. The body must support both maternal bone health and fetal skeletal development.

If intake or sun exposure is insufficient during this time, deficiency risk rises.

3. Naturally Lower Bone Density

Women generally have lower bone density than men to begin with. Combined with age-related bone loss, this increases reliance on sufficient vitamin D levels to maintain skeletal health.

Globally, about 1 in 3 women over age 50 will experience osteoporotic fractures, highlighting the importance of prevention.

4. Higher Body Fat Percentage

Vitamin D is a fat-soluble vitamin, meaning it’s stored in fat tissue. Women naturally have a higher average body fat percentage than men.

When more vitamin D is stored in fat, less circulates in the bloodstream potentially lowering measurable vitamin D levels.

5. Lifestyle and Sun Exposure

Your skin produces vitamin D when exposed to ultraviolet (UV) rays from sunlight. However, several factors may limit sun exposure:

• Indoor work environments

• Caregiving responsibilities

• Consistent sunscreen use

• Clothing that limits skin exposure

While sunscreen is essential for skin cancer prevention, it can reduce vitamin D synthesis when used consistently and correctly.

It’s also worth noting that an estimated 35% of U.S. adults are vitamin D deficient, with higher rates observed in women and individuals with darker skin tones due to reduced UV absorption.

Should Women Get Their Vitamin D Levels Checked?

Vitamin D testing is not routinely included in standard blood panels.

Because women are at higher risk for vitamin D deficiency especially during pregnancy, perimenopause, and postmenopause it’s reasonable to discuss screening with your healthcare provider.

Advocating for testing may be particularly important if you:

• Have osteoporosis or low bone density

• Experience frequent fatigue

• Have limited sun exposure

• Live in northern climates

• Have darker skin

• Are pregnant or breastfeeding

A simple blood test measuring 25-hydroxyvitamin D can determine your levels.

How Much Vitamin D Do You Need?

General recommendations suggest:

• Ages 1–70: 600 IU (15 mcg) per day

• Age 71 and older: 800 IU (20 mcg) per day

However, some individuals may require higher amounts depending on their baseline levels, medical history, and provider recommendations.

How to Increase Your Vitamin D Levels

There are three primary ways to boost vitamin D.

1. Safe Sun Exposure

Spending time outdoors can stimulate vitamin D production. Even 10–30 minutes of midday sunlight several times per week may help, depending on skin tone and location.

Balance is key avoid prolonged sun exposure without protection.

2. Dietary Sources

Few foods naturally contain vitamin D, but some options include:

• Fatty fish (like salmon and mackerel)

• Egg yolks

• Liver

Fortified foods can also help:

• Milk

• Yogurt

• Plant-based milks

• Breakfast cereals

Because dietary intake alone is often insufficient, many women rely on fortified foods or supplements.

3. Supplements

Vitamin D supplements can be effective, especially in colder months or for women with limited sun exposure.

Since vitamin D is fat-soluble, taking supplements with a meal containing healthy fats may improve absorption.

Always consult your healthcare provider before starting supplementation, particularly if you have underlying health conditions.

The Bottom Line

Vitamin D deficiency is common and women face unique biological and lifestyle factors that increase their risk. Hormonal changes, pregnancy, body composition, and limited sun exposure all contribute.

If you’re concerned about bone health, energy levels, or long-term wellness, speak with your healthcare provider about testing and appropriate supplementation. Small preventive steps today can support stronger bones and better health for years to come.

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