Vitamin D Deficiency Symptoms: What Many People Experience in Fall and Winter

If you’re exhausted, achy, or struggle every winter, this is one of the most overlooked reasons.

What Vitamin D Deficiency Causes: Symptoms, Root Causes, and Real Patient Results

Most people think of Vitamin D as the “bone vitamin,” but at Health & Vitality, we see something different every single week. Vitamin D deficiency is one of the most common, and most overlooked, contributors to fatigue, low mood (often experienced as the winter blues or seasonal depression), body pain, slow healing, and weakened immunity.

A simple blood test can reveal your Vitamin D level. When those levels are corrected, the results can be life-changing.

Why Vitamin D Matters More Than Most People Realize

Vitamin D acts like a hormone and influences nearly every system in the body. It is essential for:

• Energy production

• Mood and emotional stability

• Bone and muscle strength

• Immune resilience

• Inflammation control

• Hair growth and shedding

• Wound healing and tissue repair

Even being at the low end of the “normal” lab range can trigger symptoms. This is something we see over and over again in our patients.

Common Symptoms of Low Vitamin D

These are the most frequent symptoms we see in Vitamin D–deficient patients:

• Persistent fatigue or feeling unusually tired

• Low mood, irritability, or “seasonal depression”

• Bone or muscle pain, especially in the hips, legs, and lower back

• Frequent illness or slow recovery from colds

• Slow wound healing

• Increased hair shedding or thinning

Some people have only one or two symptoms. Others have nearly all of them, and never suspect Vitamin D is part of the cause.

Real Patient Results After Correcting Vitamin D

Case #1: Severe Muscle Pain → Major Relief in 6 Weeks

One patient came in with intense, daily body and muscle pain. Their Vitamin D level was 17, which is extremely low. After starting a high-quality Vitamin D3 + K2 supplement, they reported significant improvement within six weeks. Less pain, better mobility, and more energy.

Case #2: “I Thought It Was Just Aging…”

An older patient struggled with slow healing and ongoing discomfort. She assumed it was part of aging until her blood test revealed Vitamin D deficiency. Once she started a liquid D3 + K2 supplement, her healing, energy, and overall well-being improved noticeably within weeks.

These stories are incredibly common. Many people walk around with symptoms for months or years without realizing Vitamin D is a core part of the issue.

Why Many People Are Prone to Low Vitamin D - Especially in Fall and Winter

After about September, sunlight in much of the northern United States is no longer strong enough to support meaningful Vitamin D production, even for people who spend time outdoors daily.

Why:

1. The sun sits lower in the sky → UVB rays weaken and pass through more atmosphere.

2. Shorter days → your window for UVB exposure shrinks dramatically.

3. Colder weather = more clothing → less skin exposed to sunlight.

Vitamin D and Seasonal Depression

When patients tell us they feel “off,” emotional, tired, or mentally foggy during fall and winter, it’s often deeper than just shorter days. It’s the drop in Vitamin D.

Vitamin D plays a direct role in serotonin production, the neurotransmitter responsible for mood, motivation, focus, and emotional balance. As Vitamin D levels fall in the colder months, symptoms often appear:

• Low mood

• Irritability

• Reduced motivation

• Brain fog

• Emotional sensitivity

• Feeling unlike yourself

• Trouble waking up

• Harder time losing weight

Seasonal depression is extremely common in northern states like Utah. The encouraging news is that many people feel mentally brighter, more stable, and more energized within weeks of correcting their Vitamin D levels.

Common Root Causes of Vitamin D Deficiency

Beyond sunlight changes, these factors frequently contribute:

• Poor gut health, limiting absorption

• Autoimmune conditions or chronic inflammation

• Low dietary intake as Vit D is not found in most foods

• Obesity (Vitamin D becomes stored in fat tissue)

• Aging skin, which produces less Vitamin D

• Chronic stress disrupting hormonal pathways

Sometimes low Vitamin D is a sign that something deeper needs support, which is why a simple test can be so helpful.

Why We Recommend Vitamin D3 + K2

Supplement quality matters. Many cheap store brands contain inaccurate doses, poor-quality ingredients, or forms of Vitamin D that aren’t well absorbed.

We recommend Vitamin D3 combined with Vitamin K2 because:

• Vitamin D3 helps absorb calcium from the gut.

• Vitamin K2 directs calcium into bones and teeth, and keeps it out of arteries and soft tissues.

This combination supports bone, heart, immune, and hormonal health far better than Vitamin D alone.

How We Test Vitamin D at Health & Vitality

Testing is quick, simple, and accurate.

• A basic blood test reveals your exact level.

• Insurance typically covers it.

• If not, we offer a discounted cash option.

Once we know your level, we create a plan tailored to your needs and symptoms.

Vitamin D Quick Checklist: Should You Get Tested?

You should consider a Vitamin D test if you experience:

• Fatigue

• Low mood, especially in winter

• Frequent illness

• Muscle or bone pain

• Slow healing

• Hair shedding

• Low motivation or mental fog

If two or more resonate with you, testing is absolutely worth it.

FAQ: Common Questions About Vitamin D

How long does it take to feel better once I start supplementing?

Most people notice improvement within 3–8 weeks, depending on how low they started.

Can you get enough Vitamin D from food alone?

No. Food sources contain very small amounts. Sunlight and supplementation are the primary sources.

Can low Vitamin D affect hormones?

Yes. Vitamin D influences hormone production, immune signaling, inflammation, and mood pathways.

How often should I test my levels?

Most patients check 1–2 times per year, especially heading into or out of winter.

Your Next Steps

1. Get Your Vitamin D Levels Tested

A quick appointment gives you clarity and a personalized plan. Book with us HERE

2. Start a High-Quality Vitamin D3 + K2 Supplement

We carry a medical-grade option designed for optimal absorption and potency. Get your Vitamin D3+ K2 supplement HERE