I got this vitamin D article from Dr. Jo Turner at Skin Revision. This is a good article even though you may not live down under.
Skin cancer vs. vitamin D deficiency So if Vitamin D is good for you, but sun exposure is bad for you what are you to do? It is not an either/or situation, although this is the way the subject is portrayed at times and it is little wonder people are confused.
How much sun any single person might need depends on many things and there are some pretty clear recommendations that should help clarify the question. How much sun do I need to get my vitamin D?
Location, location, location In the sunny climes of Brisbane, Queensland, Australia (latitude 27 degrees south of the equator) where I live, we have abundant sunshine throughout the year. Even in the middle of winter our UV index frequently rises above the level that can cause skin cancers. We get plenty of vitamin D producing rays.
This is not the case everywhere in the world. People who live above 37 degrees north or south of the equator are at risk of Vitamin D deficiency. This impacts on large population centers in the Northern hemisphere. If you want to check your latitude link to latitude finder.
Vitamin D Facts :
Vitamin D is a fat soluble vitamin that maintains the calcium and phosphate levels in our bodies. It is necessary for the development of healthy bones. Without adequate vitamin D, the body begins to ’steal’ calcium from our bones which can lead to rickets in children and osteomalacia in adults.
Vitamin D also plays a role in our immune system protecting against a diverse range of diseases bowel cancer, MS, the flu and perhaps even Skin Cancer.
Where do you get Vitamin D from?
The skin needs exposure to UV radiation to produce vitamin D. It is the UVB radiation that is responsible for producing the vitamin D.
In Australia very few people are at risk of Vitamin D deficiency. Vitamin D is available in small amounts in certain foods such as milk, margarines, oily fish, fish liver oils and eggs but usually this is not enough to keep us healthy. Individuals who might not get enough Vitamin D People who live above 37 degrees north or below 37 degrees south of the equator.
The elderly, particularly those who don’t go outside very often - older people make only about 25% as much of the vitamin D in their skin as a 20-year-old who is exposed to the same amount of sunlight.
People with naturally brown or black skin, as pigment in the skin reduces the skin’s ability to produce vitamin D. Babies who are exclusively Breast fed if their mothers have low levels of vitamin D People who cover most of their body and heads with clothing and veils for cultural or religious reasons People with prolonged illnesses or disabilities who stay indoors People with diseases that cause fat mal-absorption such as coeliac disease, Crohn’s disease, pancreatic insufficiency, liver disease or cystic fibrosis.
If you fall into one of these categories, or have a relative who does, talk with your Doctor about getting your vitamin D levels tested and to discuss supplements.
A little sun goes a long way. Fortunately for most people our skin is extremely efficient at producing vitamin D. You don’t need prolonged sunbathing to get your vitamins. In fact it appears that short periods of exposure are better for producing vitamin D, and spending longer than the recommended time in a day does not mean your body will produce more vitamin D. After this level is reached excess is broken down.
The body stores vitamin D for the winter As it is fat soluble your body stores away vitamin D for the winter. In the areas of latitude above 37 degrees north and south of the equator and during your colder months (October to March in Northern hemisphere) your skin cannot make sufficient vitamin D because of low levels of UVB in winter sunlight in your part of the world. But for most people levels are built up in the summer sufficient to last through winter.
Too much Vitamin D is toxic
It is impossible to obtain too much vitamin D from the sun, once the healthy level has been achieved it is simply broken down. Vitamin D supplements however must be taken with care. Even dietary supplements with Cod Liver oil can be potentially toxic if taken in excess. So it is very important to consult with your Doctor if you believe you are at risk of deficiency and they will guide you with safe supplement doses.
Sun exposure and skin cancer- the flip side. 60,000 people worldwide die each year from skin cancer caused by too much sun exposure 9 diseases and conditions are caused by ultraviolet (UV) radiation. Melanoma is the deadliest disease caused by the sun, and the primary cause of UV-related disease in the Americas, Europe, Australia, New Zealand, Brunei, Japan and Singapore. World Health Organization (WHO).
So How much sun is needed- the answer not very much Ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen is usually sufficient to provide adequate vitamin D.
Comparing locations In Brisbane Australia latitude 27s28, 153e02.
A fair skinned person needs 5 minutes exposure to their face, arms and back of the hands per day outside of 10am to 4pm in summer to get enough vitamin D. In winter a fair skinned person needs 20 minutes exposure on the face, the backs of their hands and arms per day to get sufficient vitamin D. In latitudes more distant from the equator this increases especially in winter (as the UVB decreases more in winter the further you are away from the equator.)
In Hobart Australia Hobart, latitude 42s53, 147e19.
A fair skinned person will require 7-9 minutes in summer and 40-47 minutes in winter. A naturally dark skinned person needs approximately 3 -10 times this, depending on the degree of pigmentation.
Incidental sun exposure A lifestyle study indicated a normally active person will get on average 18 hours of incidental sun exposure per week. So everyone in Brisbane gets more than enough sun exposure fair or dark skinned, winter or summer, just going about their business.
This is not the case for all parts of the world, if you live above 37 degrees latitude north or south of the equator, or if you are in one of the risk groups discussed above. You need to discuss with your requirements with your Doctor, consider having your Vitamin D levels check and supplementation.
Some conclusions If you are risk of skin cancer and need to observe more rigorous sun protection practices you should discuss your vitamin D requirements with your Doctor
If you fall into a risk group for vitamin D deficiency or have a relative who does, discuss with your Doctor.
Sun protection is always required when the UV index is moderate or higher (above 3)
Small doses of sun exposure are more effective in producing vitamin D
Exposure need only be to face, backs of hands and arms.
Summer exposure of 5-10 minutes per day is all that is required to stimulate sufficient vitamin D in normally active and healthy individuals with fair skin.
DO NOT INCREASE YOUR SUN EXPOSURE OVER THE SAFE LEVELS.