How to Boost Your Vitamin D Levels Naturally—All Year Long

Pat BakerAugust 16, 2025

3 minute read

Older couple cycling outdoors on a sunny day, staying active and supporting their vitamin D levels. — Staying active outdoors is a simple, year-round way to support vitamin D and boost overall well-being.

Feeling drained or stuck in a slump? You might be low on vitamin D — the “sunshine vitamin” that plays a vital role in energy, immunity, and mood. If you spend most of your time indoors or live in a less sunny area, it’s easy to become deficient. The good news? You can boost your vitamin D levels naturally—all year long.

Why vitamin D matters year-round

Vitamin D helps your body absorb calcium to strengthen bones, supports your immune system, and contributes to mood stability. When your levels drop, you might experience fatigue, weakness, or even depression.

Summer:Many people avoid the sun to prevent heat exhaustion or sunburn.
Winter:Shorter days and colder weather reduce outdoor activity and sun exposure.
Indoor lifestyles:Spending most of your time indoors or living in areas with frequent cloud cover or pollution can reduce vitamin D production.

Because sunlight exposure varies so much throughout the year, it’s essential to support your vitamin D levels consistently and naturally.

Did you know? Vitamin D affects over 2,000 genes in your body—including some linked to autoimmune disease, heart health, and mood regulation.

Assortment of vitamin D-rich foods, including salmon, eggs, cheese, milk, and mushrooms, on a kitchen counter. — Vitamin D-rich foods, such as salmon, eggs, and fortified dairy products, can help maintain healthy levels.

1. Eat foods that naturally support Vitamin D

While sunlight is the best source, certain foods can help you maintain healthy vitamin D levels:

Fatty Fish: Salmon, mackerel, and tuna are rich in vitamin D and omega-3s.
Egg Yolks: Especially from pasture-raised hens.
Fortified Foods: Choose cereals, dairy products, and orange juice with added vitamin D.
Mushrooms: Maitake and UV-exposed portobello mushrooms can provide a plant-based boost. Maitake mushrooms, for example, can offer up to 562 IU per 50g when exposed to UV light—almost the full daily recommendation.
Taking vitamin D with a meal that contains healthy fat (like avocado or olive oil) may improve absorption.

Including a variety of these foods helps make up the difference when sun exposure is limited.

2. Supplement when diet isn’t enough

Food alone may not provide enough vitamin D, especially in winter. A vitamin D3 supplement is often recommended:

Dosage: A typical daily intake is 600–800 IU, but your specific needs may vary.
Testing: A blood test can confirm deficiency and help determine proper dosage.
Caution: Too much vitamin D can be harmful—always talk to your doctor first.

Some cholesterol-lowering statins can reduce vitamin D absorption, so speak with your doctor if you’re taking any medications.

Supplements are an easy, effective way to maintain healthy levels when food and sun aren’t enough.

Woman with long hair sitting in the sun, head tilted upward, and eyes closed, enjoying natural sunlight. — Spending time outdoors, even briefly, helps your body produce vitamin D naturally.

Soak up the sun—safely

Safe, regular time in the sun is one of the best natural ways to increase vitamin D:

Timing: Midday sun offers the strongest rays.
Skin exposure: Aim to expose your arms, hands, or legs for 10–30 minutes a few times a week.
Protection: Apply sunscreen to prevent burns and skin damage.

Even short, consistent sun exposure can help support your vitamin D levels.

Stay active outside

Outdoor activities such as walking, biking, or gardening offer two key health perks: exercise and natural light. Even in colder months, staying active outside boosts your mood, supports your immune system, and encourages vitamin D production.

Older African American couple running outdoors with soft sunlight in the background, symbolizing active aging and vitamin D awareness. — Older adults and individuals with darker skin may be at a higher risk of experiencing vitamin D deficiency.

Who’s most at risk for Vitamin D deficiency?

Certain individuals are more likely to experience low Vitamin D levels:

As older adults age, their skin becomes less efficient at producing Vitamin D.
People with darker skin have a reduced ability to produce Vitamin D because melanin decreases the skin’s capacity to absorb it.
Indoor workers: Less sun exposure means lower vitamin D levels.
Overweight individuals: Vitamin D can become trapped in body fat.

If you’re in one of these groups, you may need to be extra mindful of your intake.

How to check your Vitamin D levels

If you’re experiencing lingering fatigue, muscle aches, or low mood, ask your healthcare provider for a simple blood test to check your vitamin D levels. If you’re deficient, your healthcare provider can recommend a safe plan to increase your levels.

When should you seek help from a Functional Medicine Doctor

If symptoms continue despite changes, consider consulting a functional medicine doctor. They take a holistic approach to health and can help you explore personalized options like:

Customized supplement plans
Changes to an anti-inflammatory diet
Lifestyle changes to maximize sunlight and activity
Testing for other nutritional deficiencies and hormone levels that might affect absorption

Final thoughts

Vitamin D is crucial for your physical and emotional well-being. Whether from your diet, a supplement, or a walk in the sun, keeping healthy levels throughout the year can help you feel your best, stay strong, and support your long-term health.

Want more wellness insights from this author? Explore more articles by Pat Baker here.