Introducing sunburn and vitamin D estimates

The new look Sunbeam may only have launched a couple of weeks back, but there are a handful of extra features I’ve been keen to bring to the app since I started working on it way back in 2018. So I’m really happy to introduce these features as part of the latest version (2020.3), which hits the App Store today:

Personalized sunburn estimates

If you’re a Pro subscriber, Sunbeam can now estimate how quickly you might burn in the sun based on a combination of your skin type and the current UV Index. To do this Sunbeam asks you to select your skin type from one of the six skin types identified by the Fitzpatrick scale, which is commonly used by dermatologists to categorise how a patient’s skin responds to the sun. Sunbeam then uses an algorithm to calculate how quickly you might burn based on the estimated amount of UV radiation that will lead to sunburn for your skin type – known as the Minimal Erythemal Dose (MED). This calculation assumes you aren’t wearing any sunscreen and is, of course, only an estimate – how quickly you might burn depends on a whole range of factors including your own personal skin tone and sensitivity, and your immediate environment.

Personalized vitamin D estimates

Building on the personalization theme, Sunbeam Pro can now estimate how long you need to spend outside in the sun to get the amount of vitamin D you need. Vitamin D is made by our bodies from exposure to direct sunlight and is essential for healthy bones, teeth and muscles, as well as for your immune system. While you can get vitamin D from some foods (like red meat or oily fish), most people don’t get enough from their diet alone.

The US National Institutes of Health (NIH) recommend a daily vitamin D intake of 600-800 International Units (IU) for most adults. Sunbeam estimates the amount of time you need to spend in the sun to produce 1000 IU of vitamin D, which is the amount that’s often included in popular food supplements. The algorithm for calculating this is slightly more complex than for sunburn, so there are a few other things to keep in mind:

  1. How much vitamin D you produce depends on how much of your skin is exposed to the sun. The more bare skin you have, the quicker you’ll be able to produce the vitamin D you need. Sunbeam makes the assumption that about 30% of your body is exposed to the sunlight, which might be the case if you’re outside wearing shorts and a t-shirt.
  2. When the sun is very low in the sky (for example, during a Boston winter) there is mixed evidence about your body’s ability to generate vitamin D. The generally accepted advice is that you can’t. But even if you can produce vitamin D in small quantities during the winter, due to the cold weather you’re unlikely to be exposing enough of your skin to get a meaningful dose before you start to burn. Because of this Sunbeam assumes that your body won’t produce any vitamin D when the UV index is 2 or below.

As for sunburn, the amount of vitamin D your body produces is influenced by a range of environmental factors – including how you might be standing or sitting when you’re outside. So always remember that the number you see on Sunbeam is only an estimate, but hopefully a helpful one!

Hourly and daily temperature

This one’s a bit simpler to explain and doesn’t need a Pro subscription – everyone will now see daily and hourly high temperatures alongside Sunbeam’s UV forecasts.

Enjoy the update! ☀️