Should I Decrease My Vitamin D Supplement in the Summertime?
Working as a Registered Dietitian in Montana, one of the questions I hear every summer is “Now that I’m spending more time outside, should I stop taking my vitamin D supplement?”
The short answer? Maybe. However, it’s not as straightforward as many people think.
Vitamin D is unique because our bodies can make it when our skin is exposed to sunlight. During the summer months, longer days and more time outdoors can increase vitamin D production for some people. It’s easy to assume that sunshine automatically means you no longer need a supplement.
The reality is that vitamin D status depends on many factors. Where you live, your skin tone, how much skin is exposed, the time of day you’re outside, your age, sunscreen use, and even air quality can all influence how much vitamin D your body produces. Someone who spends hours gardening in July may have a very different vitamin D status than someone who works indoors all day and only gets brief periods of sun exposure.
This is why I generally avoid making blanket recommendations about stopping or reducing supplements based solely on the season. Instead, I encourage people to consider the reason they started taking vitamin D in the first place.
Were you found to have low vitamin D levels on a blood test? Has your healthcare provider recommended a specific dose because of a medical condition or risk factor? If so, it’s worth checking in with them before making changes. In some cases, maintaining the same dose year-round is appropriate.
For others who take a low-dose vitamin D supplement as general nutritional support, summer may be a reasonable time to reassess. A blood test can provide useful information if you’re unsure whether your current supplement routine still meets your needs.
I also think it’s important to remember that more isn’t always better. Vitamin D is a fat-soluble vitamin, meaning it can accumulate in the body over time. Taking large amounts unnecessarily isn’t beneficial and can sometimes cause harm.
Instead of asking whether everyone should reduce vitamin D in the summer, a better question might be “What does my body need right now?” The answer is often more individualized than a blanket recommendation.
For a more personalized assessment of your supplementation needs, reach out to a Northern Nutrition Group Dietitian today.
Written by Kylie Conner
Kylie specializes in: Oncology - supporting individuals through cancer treatment, remission, malnutrition, food aversions, enteral nutrition, and preventive strategies. PCOS & Fertility - weight-inclusive care for hormonal balance, menstrual health, and fertility support. Cardiovascular Disease - heart disease, high cholesterol, high blood pressure, and related conditions. Chronic Disease Prevention and Management - focusing on sustainable, non-restrictive approaches to improve long-term health and reduce risk.