Too much sun exposure can damage your skin, cause wrinkles, freckles, and sunburn. Over exposure to sun may also suppress your immune system and increase your risk of skin cancer.

Sunshine is essential for an active and happy life. It is our natural source of vitamin D. It promotes bone health and prevents many chronic diseases. It synchronizes the hormonal rhythms of our body. It is nature's oldest remedy for adverse moods.

A healthy lifestyle is a balanced lifestyle. It means not only a balanced diet, balanced exercise and rest, but also balanced sun exposure! While over exposure to sun light can cause skin damage, insufficient sunlight exposure can lead to vitamin D deficiency, which is associated with many health maladies. Therefore, there has been a growing consensus among many public health organizations that a balanced sun exposure is needed for our health.

Violet® is your personal guide to help optimize your sun experience. In sync with your smart phone, it tracks your sun exposure, alerts you before you are at risk of sunburn, and calculates your vitamin D generation from the sun. It is designed as a tool to encourage behavioral change toward better health, by reducing the risks while harnessing the benefit of sun. The goal is to motivate you to get outdoors and safely enjoy the sun without the fear, and to Live Ultra Healthy.

The amount of vitamin D you need each day depends on your age. Average daily recommended amounts from the Food and Nutrition Board range from 400 IU for infants (1 year old to 600 IU for teens and adults between 14-70 years old, and 800 IU for elders) 70 years old. However, some experts argue that is not enough and advocate higher vitamin D intake. For example, the Vitamin D Council recommends that healthy adults take 2,000 IU of vitamin D daily -- more if they get little or no sun exposure.

There is no one-size-fits-all answer. It varies with many factors, including but not limited to, your age, size, skin type, clothing coverage, sunscreen application, etc. Generally speaking, you should aim to have sufficient sun light to meet your daily vitamin D need without getting skin damage from the sun.

Everyone. If you have fair skin and are prone to sun burn, then Violet® is for you to help avoid over exposure to sun. If you have a dark skin or mostly stay indoors, then Violet® is for you to motivate you get out getting sun-generated vitamin D. If you are a parent caring about your children's sun health, then Violet® is for you to help improve their sun balance. No matter you are young or old; work indoors or outdoors, Violet® is here to help.

Our skin manufactures vitamin D in response to sun's ultraViolet® light in a specific spectrum (UV-B). While application of sunscreen product with high SPF can help reduce the risk of sunburn by blocking out the UV-B light, it also blocks our body's capability for vitamin D production.

Our body takes ultraViolet® radiation from the sun and uses it to synthesize vitamin D in the skin. Clothing coverage affects your body's efficiency of vitamin D synthesis. Exposing more skin will allow you to absorb more UV light and faster vitamin D generation, but more time is required the less skin that's exposed.

The American Academy of Dermatology recommends using a broad-spectrum sunscreen with an SPF of 30 or more. Apply sunscreen generously 20 to 30 minutes before going outdoors and reapply about every two hours - or more often if you're swimming or sweating. However, many studies have shown that most people only apply 25-50% of the recommended amount of sunscreen. Therefore, the effective SPF of a sunscreen product often actually deviates from the labeled SPF, and the actual length of protection time offered by sunscreen is also shorter.

These factors all contribute to your body's capability for vitamin D production. It is important to take these factors into account in our algorithm to provide personalized and more accurate calculation.

The Fitzpatrick Skin Type is a skin classification system first developed in 1975 by Harvard Medical School dermatologist Thomas Fitzpatrick, MD. This system classifies complexions and their tolerance of sunlight. Types range from the very fair (Type I) to the very dark (Type VI).

Developed based on state-of-the-art sensor technologies and advanced system miniaturization, the Violet® is the only device that offers user quantitative information on accumulated UV dosage, with built-in scientific references to its health effects, including real-time projection of time to skin damage and naturally produced vitamin D toward daily goal. Our proprietary algorithm behind these novel features are supported by a series of scientific publications. Moreover, the device can be personalized because the algorithm takes into account many individual factors such as skin type, age, body size, clothing coverage, and sunscreen usage, etc.