Is 5 Minutes of Summer Sun a Safe Amount of Time for Vitamin D?

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Check out this answer from Consensus:

While 5 minutes of summer sun exposure can contribute to Vitamin D synthesis, it is generally not sufficient to achieve optimal levels. Longer exposure times, such as 10-15 minutes, are recommended to ensure adequate Vitamin D production. It is important to balance sun exposure to maximize Vitamin D benefits while minimizing the risk of skin damage.

Vitamin D is essential for various bodily functions, including calcium and phosphate absorption, bone health, and immune system support. The primary source of Vitamin D is UVB radiation from sunlight. However, there is a delicate balance between obtaining sufficient Vitamin D and minimizing the risk of skin damage from UV exposure. This article explores whether 5 minutes of summer sun exposure is sufficient and safe for Vitamin D synthesis.

The Importance of Vitamin D

Vitamin D plays a crucial role in maintaining bone health, muscle function, and overall immunity. Deficiency in Vitamin D can lead to various health issues, including osteoporosis, muscle weakness, and increased susceptibility to infections2. The body synthesizes Vitamin D3 when the skin is exposed to UVB rays from the sun, making sunlight exposure a vital component of Vitamin D acquisition.

Recommended Sun Exposure for Vitamin D

Research indicates that short, casual exposures to summer sunlight can produce sufficient Vitamin D levels. For instance, a study conducted in the UK found that 13 minutes of midday summer sun exposure to 35% of the skin surface area was sufficient to achieve adequate Vitamin D levels, though not necessarily optimal levels1. Another study suggested that exposing the face, arms, legs, or back to sunlight for an average of 15 minutes between 10 a.m. and 3 p.m. two to three times per week is adequate for Vitamin D production2.

Is 5 Minutes Enough?

While 5 minutes of sun exposure may contribute to Vitamin D synthesis, it is generally considered insufficient for achieving optimal Vitamin D levels. Studies have shown that longer exposure times, such as 10-15 minutes, are more effective in maintaining adequate Vitamin D levels4 5. For example, research conducted in Australia and New Zealand indicated that 5-10 minutes of sun exposure during summer, with 35% of the body surface area exposed, is sufficient to maintain existing Vitamin D levels5.

Safety Considerations

While obtaining sufficient Vitamin D is important, it is equally crucial to avoid overexposure to UV radiation, which can increase the risk of skin cancer. The key is to find a balance that allows for adequate Vitamin D synthesis without causing skin damage. Short, regular exposures to sunlight, preferably during midday when UVB levels are highest, can help achieve this balance3 4.

 

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Nicholas Schwab has answered Extremely Unlikely

An expert from University of Muenster in Neurology, Immunology, Immunopathology, Immunogenetics

First off, the question seems to be two parts:

1. a) is 5 minutes of sun exposure safe with regards to the potentially damaging properties of sunlight and
2. b) are 5 minutes of sunlight enough for the human body to produce Vitamin D in sufficient quantities.

As the answers to this question are diametrically opposed, I chose to answer “extremely unlikely”, as this seems to be the more pressing question here (b).

To answer question a) In most cases 5 minutes of sun should be safe, if the person in question is not extremely sensitive to sunlight (e.g. no pigmentation at all or being exposed after long periods of no sunlight for example flying to Australia in January from a country, where there is currently winter such as Germany).

However, to answer question b) 5 minutes of sunlight will not be enough to produce adequate amounts of Vitamin D, even in caucasians, who will produce more Vitamin D, when exposed to similar amounts of UVB radiation compared to people with darker skin. Especially considering that most people would wear at least some degree of clothing, the exposure of arms, legs, and head to UVB radiation for 5 minutes will not suffice.

 

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Dianne Godar has answered Extremely Unlikely

An expert from Human Disease Research Worldwide in Biochemistry, Chemistry, Biology

Even if you are nude, 5 mins. of summer sun at noon for skin types II-III (mostly whitish skin) is inadequate to produce enough vitamin D. You would need a whole body exposure of at least 5 mins. per side to get close to making enough vitamin D for good health (but depends on latitude and altitude as well).

Five minutes exposing your hands, face, and some arm and leg (e.g., as some say walking to your car during lunch) is not enough time for a clothed person even if they have short sleeves and shorts on. The time needed also increases as you age so that by the time you are 60 or 70 you need to get 1 MED (Minimal Erythemal Dose) per day to most of your body to make enough vitamin D because you make about half as much at age 70 as you made when you were age 20. 

For somewhat ‘safe’ sun exposure to make enough vitamin D, you need to get all three of your HPV shots. Then you will probably be OK for not getting skin cancer from UVB exposure because they just proved you need the virus and UVB to get non-melanoma skin cancer in a mouse model. They used the same strain of mice with and without mouse PV and exposed them to the same doses of UVB but only the MnPV mice got skin cancer. “Using the natural model Mastomys coucha, which reflects the human situation in many aspects, we provide the first evidence that only UVB and Mastomys natalensis papillomavirus (MnPV) infection strongly promote NMSC formation.” 

Here is a link to that paper:

https://www.ncbi.nlm.nih.gov/pubmed/29190285

However, there is also photoaging so I would take the pills! I take one pill a week of 50,000 IU of Vitamin D3 that I buy on Amazon but you can probably get them elsewhere.

Healthy levels of vitamin D is debatable.

 

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Dot Bennett has answered Near Certain

An expert from St George’s, University of London in Cell Biology, Skin Cancer, Oncology

This would be pretty safe for nearly anyone in any climate, but it may not be enough for your vitamin D. It is commonly said that 15 minutes of summer sun on face and arms is enough for a “white” person to get enough vitamin D in mid-European latitudes, but the time will obviously be lower near the equator and higher in the north. And longer in cooler seasons and for darker skin.

A simple rule of thumb is that if you get sunburnt it is too long, and if you don’t, that time was sufficiently safe.

 

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Adriano Angelucci has answered Unlikely

An expert from University of L’Aquia in Cell Biology, Oncology

The evolution has determined that the main source of vitamin D for humans, and for many other terrestrial animals, is UVB radiation from sun. Accordingly, during his emigration from tropical latitudes, humans have been subjected to a strong selective pressure in order to adapt to changing geographical and climate conditions at reduced UVB irradiance, as clearly demonstrated by the dramatic change in skin type. The association of vitamin D status with latitude, climate, skin type and lifestyle suggests that causes of hypovitaminosis D should be investigated on regional bases. In general, it could be assumed that times needed for a safe exposition to sun, when adequate skin surface is exposed, is sufficient to photosynthesize in the skin the necessary concentration of vitamin D precursors. Thus, in a clear summer day, in the central hours of the day, few minutes of sun exposure could be adequate also in many regions of Europe and North America. However, because the presence of many limiting variables at high latitudes, a five-minute exposure rule is not advisable. Subjects should be aware of their skin type and of the current effective UVB radiation (eg UV-Index) and follow a simple rule: as much as possible without discomfort. Erythema is a clear signal of unnecessary sun exposure. At high latitude, starting from about 40 degree, it is to be considered that in winter, environmental conditions do not permit to photosynthesize vitamin D in the skin, and body utilizes vitamin D produced in summer and partially stored in fat tissues. For this reason it is important, for Europeans and North Americans, to charge as much as possible their vitamin D pool in summer.

 

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Ann R Webb has answered Unlikely

An expert from University of Manchester in Atmospheric Science, Photobiology

There is no straightforward answer to this question since it depends on a range of variables, beginning with the definitions of ‘safe amount of sun exposure’ and ‘healthy level of vitamin D’, followed by consideration of latitude, season, time of day, skin type and unprotected skin area exposed.

In recent work from the UK (latitudes 50-60N) we have shown that 9 minutes exposure every day (whatever the weather) in the lunchtime period during the months March to September would provide for vitamin D needs. The caveats are: 1 standard erythema dose (SED) is the maximum UV dose that could be received in the UK for this duration of exposure, so there is no risk of sunburn for the general population (our definition of ‘safe sun exposure’); ‘healthy level of vitamin D’ means the avoidance of deficiency (25(OH)D < 25 nmol/L) throughout the year; 35% skin area is exposed in June, July, August (equivalent to wearing modest shorts/skirt and T-shirt), with 10% (hands and face) exposed in the cooler months; this is for white-skinned individuals; exposure occurs in an open, unshaded place e.g. field, park, large piazza, rather than a city street surrounded by tall buildings.

In the UK there is insufficient UV radiation in sunlight from about October – February to initiate any appreciable vitamin D synthesis. Vitamin D status declines through the winter so summer exposure has to provide for winter-time vitamin D needs.  At lower latitudes than the UK the so-called vitamin D winter is shorter and the noon-time sunlight contains more UV radiation, so exposure times can be shorter. At latitudes higher than the UK the opposite is true. North America/Canada and Europe cover latitudes both higher and lower than the UK.

For people with skin type V (brown, South Asian) the equivalent exposure time in the UK is 25 minutes per day. This means the exposure maximum is a little less than 3SED, but this is also well below the sunburn limit for skin type V.

Exposing a greater area of unprotected skin (if practically possible) would enable exposure times to be reduced further. Maintaining our ‘safe sun exposure’ of 9 (or 25) minutes daily and exposing only hands and face year round does not promote sufficient vitamin D synthesis for year-round avoidance of deficiency.

Finally, redefining a ‘healthy level of vitamin D’ would change the exposure times, and the possibilities of meeting vitamin D requirements through safe sun exposure.

 

Is 5 minutes of summer sun a safe amount of time for Vitamin D?

Ulrike Lehmann has answered Unlikely

An expert from University of Bergen in Nutrition

Indeed, whether 5 minutes are enough will depend mostly on the the latitude, the type of skin, the strength of the Sunlight and UVB irradiation (which is again varying during the day). Another factor is the use of sunscreens that reduce endogenous vitamin D synthesis.

For the majority of People in Europe, 5 minutes will not be enough

Jutta Dierkes, University of Bergen, NOrway