If you’re having trouble remembering to get some sun, this new smart ring feature could help. Smart ring brand Ultrahuman just debuted a new feature that aims to support optimal vitamin D levels by tracking your sun exposure.

The Vitamin D PowerPlug, one of many add-ons users can try on the Ultrahuman app, aims to optimize sunlight intake. You plug in your skin type, and the app calculates how much time you should spend in the sun based on your location and UV index.

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So, how does it work? The Ultrahuman Ring Air uses its motion-sensing IMU (inertial measurement unit) to track your movement patterns and a PPG sensor to measure your heart rate as you move. “The ring’s ability to detect changes in environmental factors and physical activity helps it infer when you’re likely spending time outside⁠,” Mohit Kumar explained in an email to ZDNET.

Once you activate the Vitamin D PowerPlug and log an outdoor activity, like a run or bike ride, the smart ring automatically tags your estimated sunlight exposure based on the duration spent outside. “It also uses your location to get real-time data on the UV index specific to the region you live. This helps you understand your sunlight exposure in context to your environment, making your Vitamin D tracking more precise,” Kumar said.

You won’t have to manually log physical activity performed outside since the ring automatically captures that. Still, you will have to log how much time you spend outside in the sun if you’re sedentary, like sitting on a beach or reading outside.

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Vitamin D is an essential nutrient that impacts our health and wellness. You can get Vitamin D through some foods, like cheese, milk, fatty fish, egg yolks, and more. But you can also get Vitamin D simply by going outside when it’s sunny out. That’s easier said than done. According to the National Institutes of Health, one in four people in the US isn’t getting adequate amounts of Vitamin D.

The PowerPlug is supposed to make maintaining healthy Vitamin D levels “effortless and personalized,” according to Ultrahuman’s description.

I tested the feature for myself and found it helpful when I was active outside wearing the ring. Getting automatic sun exposure detections when I was on runs or walks was pleasant and seamless. Remembering to log my sun activity was the greatest challenge since I found myself outside for a few minutes throughout the day and would forget to clock that time in the app. But when I did remember, it was cool to see the daily percentages.

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This feature is fun to use — especially during the summer when catching rays is easy. I also imagine it could help those with seasonal affective disorder in the colder and grayer months and remind them to spend more time outside.

The Vitamin D tracking PowerPlug is one of many Ultrahuman offers in the app. There’s a cardio adaptability PowerPlug that monitors your heart activity throughout the night, a Circadian alignment PowerPlug, a jet lag PowerPlug, a screentime PowerPlug, and more.

As more smart rings are released, from notable companies like Samsung to niche brands like RingConn, smart ring brands are developing more innovative features, like Ultrahuman’s Vitamin D PowerPlug, to make a case for their product.