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Originally Posted by mommysunshine
Hi guys,
I have two questions about vit. D intake/production:
1.) I live in California near San Diego (approx. 35 degress longitutinal). Can I make vit. D from being in the sun midday in the wintertime? It's a gorgeous sunny day today. Does my shadow need to be shorter than my height?
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YES If your shadow is longer than you are tall it's inevitable that the UVB rays will have passed through too much atmosphere and the UVB that does reach ground level will be too little to generate vitamin d.
You have to understand that UVA degrades vitamin D and you can't get UVB without UVA so if the amount of UVA overwhelms the UVB it's inevitable that the downgrading will totally counteract the creation so you end up with a net loss.
That does not mean it is not a good idea to be outside during the day when the light is bright.
Your circadian rhythm is set by bright light exposure and melatonin is in many ways equally as important an anti inflammatory agent as is vitamin d3.
Whereever you live you also have to bear in mind that OZONE blocks UVB penetration to ground level and so if you live in town near a busy road, under an aircraft flightpath or downwind of industrial processing it's possible the ozone created will be preventing sufficient vitamin D creation.
here is one example of the difference between urban/rural vitamin d creation.
UrbanTropospheric Ozone Increases the Prevalence of Vitamin D Deficiency among Belgian Postmenopausal Women with Outdoor Activities during Summer
This time of year it's not too bad but if there's no chance of sufficient UVB reaching ground level anyway it's a bit of a non starter.
San Diego Ozone pollution map
I should also point out that where your local agriculture is very industrialized, and a high level of fertilizer is applied, in summer this is suffient to also generate ozone, it's sufficient to reduce crop yields by 10~20% so will also reduce the potential for vitamin d creation.
25(OH)D levels have been declining year on year for many years now.
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2.) I buy sheep feet and necks and at a local Persian market to make broth.
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BUY?
Where I live they give bones away for making stock. For goodness sake don't come to the UK and start butchers SELLING bones. They charge enough for meat anyway they don't want any encouragement to actually start charging for bones as well.
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Lanolin is a source of vit. D so I was thinking the sheep feet which has approx. 6 inches of skin attached would be an excellent form of vit. D in food. I haven't seen any recipes or sites saying this is true so maybe it isn't. Anyone know?
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Vitamin D is very robust and certainly survives the heat in the baking process however I'm not certain that lanolin before UVB irradiation actually contains vitamin D3.
Maybe if you left the sheep trotters under UVB (sunbed?) you may stand a better chance. I think it's safe to take a 5000iu vitamin d capsule daily myself.
Grassrootshealth do 25(OH)D testing by post to make sure what you are doing is working for you.