The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

any research on sourdough & vitamin D?

claire_bug's picture

any research on sourdough & vitamin D?

Hello all,

I recently stumbled upon fresh yeast cakes that are exposed to light, thereby creating Vitamin D.  Here's a quote from the manufacturer of the yeast:

"Lallemand’s yeast is exposed to a source of light during the regular production process that naturally transforms the sterols present in yeast into vitamin D."

Ok, so why not sourdough? If I leave my starter out to warm in the sunlight, and I leave my sourdough bread out to rise in the sun, perhaps there too is a source of Vitamin D.  Anyone seen or heard of any research that has been done on sunlight and sourdough?


Thank you. 

nicodvb's picture

Mind, temperature may rise a lot inside the container when exposed to the sunlight.

Last year I prepared a panettone and I let it raise in a tranparent plastic box near the window. After one hour I checked the temperature inside and shock! it was in excess of 60°C!!

As for vitamin D I don't know.

Mini Oven's picture
Mini Oven

Chemistry: There are two chemical forms of vitamin D, namely vitamin D2 (sometimes referred to as ergocalciferol) and vitamin D3 (sometimes referred to a cholecalciferol). The natural form of vitamin D for animals and man is vitamin D3 that is produced in their bodies from cholesterol and 7-dehydrocholesterol. An alternative vitamin D2 is derived from the yeast sterol ergosterol by chemical procedures.

I was under the impression that sunlight's UV radiation kills many types of yeast cells depending on the exposure.  

To expose yourself to the sun is the most natural way to aquire vitamin D3 and during the most sunny part of the day for about 15 minutes in high summer.  I don't think the little yeasty beasties can match our skin's abilities.  Strip and get out in the sun!   Leave the sunscreen and sourdough inside.  


EvaB's picture

a bottle of the D3, which is cheap enough and you get something like 300 in the bottle from KIirkland at Costco, all I know is if you live above the middle of the world, you don't get enough from sunlight. Anyone who lives in the North of Canada and most of Europe don't get enough sunshine to get enough D production.

I stopped sunburning when I started taking vitamin D in 1000 unit doses three times a day, I feel better and while it hasn't cured my diabetes, it sure seems to have helped the fibromyalgia to a great extent.

When I say stopped sunburning, I mean that less than 5 minutes outside on a sunny day was enough to leave me with a bad burn, now I can spend hours outside and not burn badly, yes I will burn a bit, but not nearly as badly as before, I blistered!