alternative-health
SOURCE:
The calculator at http://nadir.nilu.no/~olaeng/fastrt/VitD-ez_quartMED.html which is meant for use in the Northern Hemisphere, so must be offset by 6 months, for use in the Southern Hemisphere (their December is cold; ours is hot!).
NOTE:
This table of values has been calculated for a latitude of 36 degrees, South, (Adelaide, Australia; elevation: 0.150 km) and involves certain basic assumptions, such as age, and ozone levels, which may, or may not be applicable, so should be taken as a rough guide only.
Advice from a pathologist is that around half of the samples of blood being tested at present are returning results which show that the levels of vitamin D3 are either depleted, or deficient, at the end of winter. It is most pronounced with the elderly, (we become progressively less efficient at converting sunlight to vitamin D3 as we age) but, concerningly, also applies to young adults.
It may well be that the recent media campaigns about skin cancer have scared many people into not getting regular exposure to sunlight, sufficient to maintain healthy levels of this vital nutrient, which is involved in hundreds of biochemical reactions in the body.
The exposure times need to be interpreted in terms of the information at the above website, as they are based on the exposure of the face, hands, and arms, (25% of the skin surface) EVERY OTHER DAY, sufficient to produce 25 micrograms of vitamin D3, and must be adjusted, according to the levels required by that person. This would need to take into consideration factors such as the dietary intake, and supplements taken, and whether any vitamin D added is vitamin D3, or vitamin D2; only a small proportion of the latter is converted into vitamin D3 in the human body. Dr. Joseph Mercola, at http://www.mercola.com (which is the most visited natural health website in the world; I suggest that you sign up for their regular free Ezine) and Dr. Ben Kim both recommend that optimal levels of 115 nmol/l - 125 nmol/l be maintained, all year round. People with cancer (EXCEPT SARCOIDOSIS) need considerably more.
Empirically, I can inform you that, as a pale skinned Caucasian male 55 years of age, I exposed 100% of my skin to the sun, for 8 minutes per side, on both sides at around 8AM, during the summer months, registering 114 nmol/l)". Had weather conditions been ideal, I estimate that it would have been 120 nmol/l)". During the winter months, I took 4 x 1000 IU of vitamin D3 daily, registering 93 nmol/l), which was still a lot better than the depleted level of 49 nmol/l that I scored in my first test. Next winter, I intend to supplement at a rate of 5 x 1000 IU daily.
You may need less, or more, according to such variables as your weight, and genetics, but, generally speaking, I prefer to adopt a conservative approach to supplements. High levels of vitamin D3 (cholecalciferol) cause unhealthy deposits in the arteries. It is important to maintain good levels of magnesium, zinc, and calcium, to ensure proper utilisation of vitamin D3, and helps keep bones strong. Weight bearing exercise can help considerably in this process, as well. Try pharmacies or vitamin & health food stores for the magnesium supplement types shown in http://www.real-depression-help.com/magnesium-for-depression.html
Dr. Mercola advises that the human body has a self limiting process for vitamin D3 production, so you won't form too much (but you could still get sunburnt). He also states that it is formed near the surface of the skin, and to avoid washing more than the armpits and groin, if using soap in a shower, within 48 hrs of sunlight exposure, otherwise a considerable amount will be dissolved, and washed away.
Go to a doctor and ask for a 25(OH)D, also called 25-hydroxyvitamin D, blood test. When you get the results, don’t follow the typical “normal” reference range, as these are too low. The OPTIMAL value that you’re looking for is 45-52 ng/ml (115-128 nmol/l)".
See http://articles.mercola.com/sites/articles/archive/2008/12/16/my-one-hour-vitamin-d-lecture-to-clear-up-all-your-confusion-on-this-vital-nutrient.aspx (U.S.A. only: INSIST ON the following, or be misled! "The correct test is 25(OH)D, also called 25-hydroxyvitamin D" - "I strongly recommend using LabCorp for these reasons until Quest can guarantee accurate, usable results."
From Mercola.com - Enter: TEST VALUES FOR VITAMIN D DEFICIENCY in their searchbar). I recommend having one test to establish your current level, and if depleted, or deficient, take action accordingly. Then have at least one test, at the end of winter, when your levels should be at their lowest, and make the necessary adjustments. It is a good idea to have another test, at the end of summer, when, if you are not supplementing vitamin D3, your levels should be at their highest.
If you get sufficient exposure to the sun, then take supplements, you can be overdosing on vitamin D3, so it's important to reduce, or increase your supplementation rate, according to the season, the weather conditions, and exposure time for that time of day. Always err on the side of caution; it's far preferable to underdose, than overdose.
________________________________________________________________________________________________________
From: http://nadir.nilu.no/~olaeng/fastrt/README_VitD-ez_quartMED.html
"The current model has undergone internal checking and validation. If you have any questions or comments on this service and how it could be improved for your needs, please contact the author.
If you use this program and publish the results, I would appreciate a lot if you cite it:
Ann R. Webb and Ola Engelsen: Calculated ultraviolet exposure levels for a healthy vitamin D status, Photochemistry and Photobiology, 2006, doi: 10.1562/2005-09-01-RA-670, 2006, reprint freely available on the internet at http://www.nilu.no/index.cfm?ac= publications&folder_id=4309&publication_id=16084&view=rep&lan_id=3
The underlying simulations are done using the following model:
Engelsen O. and Kylling A., Fast simulation tool for ultraviolet radiation at the Earth's surface. Optical Engineering, 44 (4), 041012 (2005).
A user interface and more information about this model is available at http://nadir.nilu.no/~olaeng/fastrt/fastrt.html. This model interface has mostly the same input options as the VitD web tool.
VitD-ez_quartMED changelog
Method outline (see the journal article above for details) FastRT was used to compute erythema [MacKinley and Diffey, 1987] and vitamin D effective [MacLaughlin et al., 1982] UV doses. The former were expressed in standard erythemal units (SED = 100 Jm-2 erythemally effective UV, which for skin type I = half Minimal Erythemal Dose, MED). The latter were computed using the action spectrum for conversion of 7-DHC to previtamin D in human skin [MacLaughlin et al., 1982] with an exponential decay extrapolation. We then defined a Standard Vitamin D Dose (SDD) corresponding to the UV equivalent of an oral dose of 1000 IU vitamin D [Holick 2004c] i.e. the dose recommended to gain all the possible health benefits of vitamin D [Holick, 2004a]. Since radiation is incident on the skin, and the response to either irradiation or oral dosing is measured in the blood, the SDD must be qualified by the conditions of skin exposure. Following the formula of Holick [2004a] that recommends exposure to a quarter of a personal MED on a quarter of the skin area (hands, face and arms), we calculated the equivalent D effective UV. We calculated UV doses for a mid-latitude midday in spring (Boston, 21 March, 42.2 degrees N, ozone = 350DU) when it is known that vitamin D can be synthesised in the skin. This latter assumption is based on the work of Webb et al. (1988) who showed that from November to February there was insufficient solar UVB to synthesise vitamin D in Boston, but by March previtamin D was formed from 7-DHC in both solution and the skin. From this we calculated the time to acquire a quarter MED (= half SED for a fair skinned person). Using the same solar exposure we then calculated the vitamin D effective dose acquired over the same time interval. This is then the SDD based on exposure of a quarter body surface area, and is equivalent to 37.2 Jm-2 vitamin D effective UV for the cloudless conditions above, corresponding to about 16 minutes of exposure at solar noon. A fair skinned person exposing hands, face and arms (ca. 25% of the body) would now make sufficient vitamin D with 1 SDD, and will suffer a minimal erythema after 1 MED (2 SED), which by definition is 4 times the SDD exposure in these reference conditions (i.e. Boston, 21 March, 42.2 degrees N, ozone = 350 DU). Darker skinned people will require both multiple SDDs and a greater number of SEDs to achieve the same effects.
The recommended blood serum level is under debate [Dawson-Hughes et al., 2005], but 30 ng/mL is widely recommended e.g., by [Hollis, 2005]. Clinical studies found 500-1,000 IU of vitamin D/day maintains blood serum levels of 30 ng/mL (75 nmol/L) [Tangpricha et al, 2003], [Heaney et al., 2003], [Meier et al., 2004].
In order to assess the fraction of the body that is exposed to the sun, the Lund and Browder Chart for skin burns provides an indication: Face 3.5%, neck 2%, trunk 26%, hands 6%, arms 14%, legs 14%, thighs 18%.
Output The resulting output, recommended UV exposure to obtain sufficient vitamin D, is two numbers in a single row at the bottom, i.e. hours:minutes." ~~~
________________________________________________________________________________________________________
SKIN TYPE: TIME: SKY CONDITION: SURFACE: RECOMMENDED EXPOSURE TIME* (HOURS:MINUTES)
________________________________________________________________________________________________________
SKIN TYPE: TIME: SKY CONDITION: SURFACE: RECOMMENDED EXPOSURE TIME ( HRS: MNS)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SKIN TYPE: Pale Caucasian. TIME: 9.00AM. SKY: Clear. SURFACE: Concrete. RECOMMENDED EXPOSURE: 9 MINUTES.
SKIN TYPE: TIME: SKY CONDITION: SURFACE:
SKIN TYPE: TIME: SKY CONDITION: SURFACE:
= 9 mns @ 25% of skin surface for 1000 IU. For 5000 IU = 9 x 5 = 45 mns = around 22 mns daily, FOR GRASS/LAWN, or CONCRETE.
The calculator at http://nadir.nilu.no/~olaeng/fastrt/VitD-ez_quartMED.html which is meant for use in the Northern Hemisphere, so must be offset by 6 months, for use in the Southern Hemisphere (their December is cold; ours is hot!).
NOTE:
This table of values has been calculated for a latitude of 36 degrees, South, (Adelaide, Australia; elevation: 0.150 km) and involves certain basic assumptions, such as age, and ozone levels, which may, or may not be applicable, so should be taken as a rough guide only.
Advice from a pathologist is that around half of the samples of blood being tested at present are returning results which show that the levels of vitamin D3 are either depleted, or deficient, at the end of winter. It is most pronounced with the elderly, (we become progressively less efficient at converting sunlight to vitamin D3 as we age) but, concerningly, also applies to young adults.
It may well be that the recent media campaigns about skin cancer have scared many people into not getting regular exposure to sunlight, sufficient to maintain healthy levels of this vital nutrient, which is involved in hundreds of biochemical reactions in the body.
The exposure times need to be interpreted in terms of the information at the above website, as they are based on the exposure of the face, hands, and arms, (25% of the skin surface) EVERY OTHER DAY, sufficient to produce 25 micrograms of vitamin D3, and must be adjusted, according to the levels required by that person. This would need to take into consideration factors such as the dietary intake, and supplements taken, and whether any vitamin D added is vitamin D3, or vitamin D2; only a small proportion of the latter is converted into vitamin D3 in the human body. Dr. Joseph Mercola, at http://www.mercola.com (which is the most visited natural health website in the world; I suggest that you sign up for their regular free Ezine) and Dr. Ben Kim both recommend that optimal levels of 115 nmol/l - 125 nmol/l be maintained, all year round. People with cancer (EXCEPT SARCOIDOSIS) need considerably more.
Empirically, I can inform you that, as a pale skinned Caucasian male 55 years of age, I exposed 100% of my skin to the sun, for 8 minutes per side, on both sides at around 8AM, during the summer months, registering 114 nmol/l)". Had weather conditions been ideal, I estimate that it would have been 120 nmol/l)". During the winter months, I took 4 x 1000 IU of vitamin D3 daily, registering 93 nmol/l), which was still a lot better than the depleted level of 49 nmol/l that I scored in my first test. Next winter, I intend to supplement at a rate of 5 x 1000 IU daily.
You may need less, or more, according to such variables as your weight, and genetics, but, generally speaking, I prefer to adopt a conservative approach to supplements. High levels of vitamin D3 (cholecalciferol) cause unhealthy deposits in the arteries. It is important to maintain good levels of magnesium, zinc, and calcium, to ensure proper utilisation of vitamin D3, and helps keep bones strong. Weight bearing exercise can help considerably in this process, as well. Try pharmacies or vitamin & health food stores for the magnesium supplement types shown in http://www.real-depression-help.com/magnesium-for-depression.html
Dr. Mercola advises that the human body has a self limiting process for vitamin D3 production, so you won't form too much (but you could still get sunburnt). He also states that it is formed near the surface of the skin, and to avoid washing more than the armpits and groin, if using soap in a shower, within 48 hrs of sunlight exposure, otherwise a considerable amount will be dissolved, and washed away.
Go to a doctor and ask for a 25(OH)D, also called 25-hydroxyvitamin D, blood test. When you get the results, don’t follow the typical “normal” reference range, as these are too low. The OPTIMAL value that you’re looking for is 45-52 ng/ml (115-128 nmol/l)".
See http://articles.mercola.com/sites/articles/archive/2008/12/16/my-one-hour-vitamin-d-lecture-to-clear-up-all-your-confusion-on-this-vital-nutrient.aspx (U.S.A. only: INSIST ON the following, or be misled! "The correct test is 25(OH)D, also called 25-hydroxyvitamin D" - "I strongly recommend using LabCorp for these reasons until Quest can guarantee accurate, usable results."
From Mercola.com - Enter: TEST VALUES FOR VITAMIN D DEFICIENCY in their searchbar). I recommend having one test to establish your current level, and if depleted, or deficient, take action accordingly. Then have at least one test, at the end of winter, when your levels should be at their lowest, and make the necessary adjustments. It is a good idea to have another test, at the end of summer, when, if you are not supplementing vitamin D3, your levels should be at their highest.
If you get sufficient exposure to the sun, then take supplements, you can be overdosing on vitamin D3, so it's important to reduce, or increase your supplementation rate, according to the season, the weather conditions, and exposure time for that time of day. Always err on the side of caution; it's far preferable to underdose, than overdose.
________________________________________________________________________________________________________
From: http://nadir.nilu.no/~olaeng/fastrt/README_VitD-ez_quartMED.html
"The current model has undergone internal checking and validation. If you have any questions or comments on this service and how it could be improved for your needs, please contact the author.
If you use this program and publish the results, I would appreciate a lot if you cite it:
Ann R. Webb and Ola Engelsen: Calculated ultraviolet exposure levels for a healthy vitamin D status, Photochemistry and Photobiology, 2006, doi: 10.1562/2005-09-01-RA-670, 2006, reprint freely available on the internet at http://www.nilu.no/index.cfm?ac= publications&folder_id=4309&publication_id=16084&view=rep&lan_id=3
The underlying simulations are done using the following model:
Engelsen O. and Kylling A., Fast simulation tool for ultraviolet radiation at the Earth's surface. Optical Engineering, 44 (4), 041012 (2005).
A user interface and more information about this model is available at http://nadir.nilu.no/~olaeng/fastrt/fastrt.html. This model interface has mostly the same input options as the VitD web tool.
VitD-ez_quartMED changelog
Method outline (see the journal article above for details) FastRT was used to compute erythema [MacKinley and Diffey, 1987] and vitamin D effective [MacLaughlin et al., 1982] UV doses. The former were expressed in standard erythemal units (SED = 100 Jm-2 erythemally effective UV, which for skin type I = half Minimal Erythemal Dose, MED). The latter were computed using the action spectrum for conversion of 7-DHC to previtamin D in human skin [MacLaughlin et al., 1982] with an exponential decay extrapolation. We then defined a Standard Vitamin D Dose (SDD) corresponding to the UV equivalent of an oral dose of 1000 IU vitamin D [Holick 2004c] i.e. the dose recommended to gain all the possible health benefits of vitamin D [Holick, 2004a]. Since radiation is incident on the skin, and the response to either irradiation or oral dosing is measured in the blood, the SDD must be qualified by the conditions of skin exposure. Following the formula of Holick [2004a] that recommends exposure to a quarter of a personal MED on a quarter of the skin area (hands, face and arms), we calculated the equivalent D effective UV. We calculated UV doses for a mid-latitude midday in spring (Boston, 21 March, 42.2 degrees N, ozone = 350DU) when it is known that vitamin D can be synthesised in the skin. This latter assumption is based on the work of Webb et al. (1988) who showed that from November to February there was insufficient solar UVB to synthesise vitamin D in Boston, but by March previtamin D was formed from 7-DHC in both solution and the skin. From this we calculated the time to acquire a quarter MED (= half SED for a fair skinned person). Using the same solar exposure we then calculated the vitamin D effective dose acquired over the same time interval. This is then the SDD based on exposure of a quarter body surface area, and is equivalent to 37.2 Jm-2 vitamin D effective UV for the cloudless conditions above, corresponding to about 16 minutes of exposure at solar noon. A fair skinned person exposing hands, face and arms (ca. 25% of the body) would now make sufficient vitamin D with 1 SDD, and will suffer a minimal erythema after 1 MED (2 SED), which by definition is 4 times the SDD exposure in these reference conditions (i.e. Boston, 21 March, 42.2 degrees N, ozone = 350 DU). Darker skinned people will require both multiple SDDs and a greater number of SEDs to achieve the same effects.
The recommended blood serum level is under debate [Dawson-Hughes et al., 2005], but 30 ng/mL is widely recommended e.g., by [Hollis, 2005]. Clinical studies found 500-1,000 IU of vitamin D/day maintains blood serum levels of 30 ng/mL (75 nmol/L) [Tangpricha et al, 2003], [Heaney et al., 2003], [Meier et al., 2004].
In order to assess the fraction of the body that is exposed to the sun, the Lund and Browder Chart for skin burns provides an indication: Face 3.5%, neck 2%, trunk 26%, hands 6%, arms 14%, legs 14%, thighs 18%.
Output The resulting output, recommended UV exposure to obtain sufficient vitamin D, is two numbers in a single row at the bottom, i.e. hours:minutes." ~~~
________________________________________________________________________________________________________
SKIN TYPE: TIME: SKY CONDITION: SURFACE: RECOMMENDED EXPOSURE TIME* (HOURS:MINUTES)
________________________________________________________________________________________________________
SKIN TYPE: TIME: SKY CONDITION: SURFACE: RECOMMENDED EXPOSURE TIME ( HRS: MNS)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SKIN TYPE: Pale Caucasian. TIME: 9.00AM. SKY: Clear. SURFACE: Concrete. RECOMMENDED EXPOSURE: 9 MINUTES.
SKIN TYPE: TIME: SKY CONDITION: SURFACE:
SKIN TYPE: TIME: SKY CONDITION: SURFACE:
= 9 mns @ 25% of skin surface for 1000 IU. For 5000 IU = 9 x 5 = 45 mns = around 22 mns daily, FOR GRASS/LAWN, or CONCRETE.
