**Title: Denver's Vitamin D Myth: High Altitude, Low Results?**

By Franklin Everett Shaw

February 20, 2026

Are you basking in the Denver sunshine, thinking you’re swimming in Vitamin D? Think again. The Mile High City’s altitude and unique climate present a deceptive challenge to maintaining optimal Vitamin D levels, even with all that glorious sunshine. This isn’t just about feeling a little tired; it’s about bone health, immune function, and overall well-being.

Many Denver residents mistakenly believe that living in a sunny, high-altitude location guarantees sufficient Vitamin D. This is a dangerous assumption. Let’s dive into why, and more importantly, what you can do about it.

The reality is that altitude, cloud cover, and lifestyle factors significantly impact Vitamin D synthesis. Denver’s higher elevation means a thinner atmosphere, which filters out some of the UVB rays needed for Vitamin D production in the skin.

Cloud cover, even on seemingly sunny days, can further reduce UVB exposure. And let’s be honest, how many of us are spending hours outdoors, exposed skin and all, during the workday?

So, how do you know if you’re actually deficient? The first step is testing.

Don’t rely on guesswork or assumptions. A simple blood test, specifically measuring 25-hydroxyvitamin D [25(OH)D], is the gold standard.

Many primary care physicians in Denver routinely include Vitamin D testing in annual physicals. However, it’s crucial to ask specifically for this test.

Some doctors may only order it if you present with specific symptoms, such as fatigue, bone pain, or muscle weakness. Be proactive about your health.

If your doctor doesn’t routinely test Vitamin D, or if you want more frequent monitoring, several options are available in the Denver area.

• Direct-to-consumer labs: Companies like Quest Diagnostics and Labcorp have locations throughout Denver and offer Vitamin D testing without a doctor’s referral. You can order the test online, visit a local lab for blood draw, and receive your results electronically. This offers convenience and affordability.
• Specialty clinics: Some clinics in Denver specialize in hormone and nutrient testing, offering comprehensive assessments of Vitamin D and other essential nutrients. These clinics often provide personalized recommendations based on your results.
• Functional medicine practitioners: Functional medicine doctors take a holistic approach to health and often prioritize Vitamin D testing as part of their overall assessment. They can help identify underlying factors contributing to deficiency and develop a tailored treatment plan.

When choosing a testing method, consider cost, convenience, and the level of support you need. Direct-to-consumer labs are generally the most affordable, while specialty clinics and functional medicine practitioners offer more personalized guidance.

Once you have your results, understanding them is crucial. Optimal Vitamin D levels are generally considered to be between 30 and 50 ng/mL. Levels below 30 ng/mL indicate insufficiency, while levels below 20 ng/mL indicate deficiency.

Don’t panic if your results are low. Vitamin D deficiency is common, especially in Denver. The good news is that it’s usually easily corrected.

The primary strategies for increasing Vitamin D levels are diet and supplementation.

Dietary sources of Vitamin D are limited. Fatty fish (salmon, tuna, mackerel), egg yolks, and fortified foods (milk, cereal) contain Vitamin D, but often not enough to meet daily needs, especially if you’re deficient.

Supplementation is often necessary to achieve optimal levels. Vitamin D3 (cholecalciferol) is the preferred form, as it’s more effective at raising blood levels than Vitamin D2 (ergocalciferol).

The appropriate dosage of Vitamin D3 varies depending on your initial levels and individual needs. A common starting dose for adults with deficiency is 5,000 IU per day, but it’s best to consult with a healthcare professional to determine the right dose for you.

Challenge: Many people start taking Vitamin D supplements without retesting their levels. This can lead to either continued deficiency or, in rare cases, toxicity.

Solution: Retest your Vitamin D levels after 3-6 months of supplementation to ensure you’re on track. Adjust your dosage as needed based on your results.

Another common pitfall is inconsistent supplementation. Forgetting to take your Vitamin D supplement regularly can hinder progress.

Solution: Incorporate Vitamin D supplementation into your daily routine. Set a reminder on your phone or keep your supplements in a visible location.

Beyond diet and supplementation, optimizing your lifestyle can also support Vitamin D synthesis.

• Sun exposure: Aim for 15-20 minutes of midday sun exposure with exposed skin (arms, legs, face) several times per week. Be mindful of sunburn risk and use sunscreen when necessary.
• Consider your skin tone: Individuals with darker skin pigmentation require more sun exposure to produce the same amount of Vitamin D as those with lighter skin.
• Be aware of sunscreen: Sunscreen blocks UVB rays, so it can inhibit Vitamin D synthesis. Use sunscreen when necessary to protect against sunburn, but consider spending some time in the sun without it.

Living in Denver presents unique challenges to maintaining optimal Vitamin D levels. The altitude, climate, and lifestyle factors can all contribute to deficiency.

However, by understanding these challenges and taking proactive steps to assess your Vitamin D status, optimize your levels through diet and supplementation, and choose the right testing methods, you can ensure you’re getting enough of this essential nutrient.

Don’t let the Denver sunshine fool you. Take control of your Vitamin D levels and reap the benefits of optimal health. Find a local Denver doctor or lab today and get tested. Your bones, your immune system, and your overall well-being will thank you.