Indeed. More than 80% of cholesterol is made by the body itself. Prominent risk factors of high cholesterol include:
Advanced Nutrition and Human Metabolism by Gropper is the book my university classes on nutritional biochemistry used. Difficult to comprehend for the lay person but great for those with a decent background in organic and biochemistry. I notice it is uber expensive on this link from Amazon but look up and get an old edition or even look around for a PDF or something.
http://www.amazon.com/Advanced-Nutrition-Metabolism-Sareen-Gropper/dp/1133104053
Also, pages like this may be of interest.
https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
Lastly, I believe you can find and read the Dietary Reference Intakes as PDF online but that doesn't focus too much on biochemistry.
Good luck and hope that helps!
edit - that's the one I have, here's the latest edition
Thanks for the feedback! Good stuff. ��
First, let me be very clear that I'm not a professional nutritionist but just a happy amateur. So take everything from here on out with a big grain of salt.
You have a good point. Two things though:
445.4 µg B12 above what IF can handle would then mean up to 20.7 µg B12 absorbed through diffusion (3 µg daily average).
ln(Ai) = 0.7694 * ln(Di) - 0.9614
) which is to say that any microgram added is absorbed at a lower and lower percentage but the overall B12 absorption does go up.500 would mean: e ^ (0.7694 * ln(500) - 0.9614) = 45.6 µg absorbed (6.5 µg daily average).
I think the key part in their quote on maximum absorption is "amounts usually consumed with a meal". With supplements we've seen much higher levels of absorption than the 1.5 µg they talk about. More than 54.6 µg + passive diffusion can explain.
I highly recommend Advanced Nutrition and Human Metabolism for these types of inquiries
Advanced Nutrition and Human Metabolism
Do your own research.
Gropper and Stipanuk are two well-rounded general nutrition texts.
I wrote a book for people w/o any biochemistry background: The poor, misunderstood calorie.
The metabolism textbook I had in college: http://www.amazon.com/Advanced-Nutrition-Metabolism-Sareen-Gropper/dp/1133104053