Sunday, December 5, 2010

Cholesterol in a Vitamin D Economy

Understanding cholesterol in a vitamin D economy…

A few definitions…

Cholesterol is a waxy steroid metabolite found in the cell membranes and transported in the blood plasma of all animals.[2] It is an essential structural component of mammalian cell membranes, where it is required to establish proper membrane permeability and fluidity. In addition, cholesterol is an important component for the manufacture of steroid hormones (autocrine activated steroid 25(OH)D, bile acids, and fat-soluble vitamins including Vitamin A, Vitamin D, Vitamin E, and Vitamin K.

Triglycerides are a type of lipid found in your blood. When you eat, your body converts any calories it doesn't need to use right away into triglycerides. The triglycerides are stored in your fat cells. Later, hormones release triglycerides for energy between meals. If you regularly eat more calories than you burn, particularly "easy" calories like carbohydrates and fats, you may have high triglycerides (hypertriglyceridemia).

Hepatic Lipase produced in the liver chops up and clears triglycerides.

HDL cholesterol’ excess cholesterol in tissue being returned to the liver. Tissue can also produce cholesterol sending it to the liver via HDL.

LDL cholesterol is sent out from the liver to cells needing cholesterol. LDL is easily damaged in the serum by toxins, oxygen free radicals and free glucose. Once damaged it is collected by macrophages and returned to the liver.

Macrophage a type of white blood that ingests (takes in) foreign material. Macrophages are key players in the immune response to foreign invaders such as infectious microorganisms.
So how is this supposed to work with “naturalized” (sunlight on skin) serum vitamin D?

When there is sufficient vitamin D it spurs tissue outside the liver to produce cholesterol. The type of cholesterol produced in tissue is HDL and it is returned to the liver as an investment. You can view this as the liver being an investment banker, and the tissues of the body are buying vitamin D while the currency is cholesterol. This means if there is sufficient serum vitamin D it instructs cells “hey if you make excess cholesterol and send it to the liver via HDL you can have some more vitamin D”. A fair trade on tissue investment. The liver then pushes the investment of HDL to the skin where it is exposed to UVB radiation which produces vitamin D and the bargain is complete 24 hours later.

LDL cholesterol being sent to cells from the liver is the inverse. Cells are not producing enough cholesterol themselves, most likely due to a lack of vitamin D stimulus. Keeping in mind that cells can hydroxilize D3 to 25(OH)D the active steroid hormone which they need for proper operation. LDL is much like a monetary stimulus package offered by the government. The tissues are not producing HDL as they should due to a lack of confidence of a fair return of vitamin D for their HDL cholesterol brought on by insufficient serum vitamin D return. The tissues are awaiting vitamin D to “Show me the money!”. If the cells do not expect a fair return on their HDL investment HDL production goes down. With HDL down LDL goes up. LDL is a hand out to tissues, when the biological economy downturns due to lack of vitamin D. We all know that hand outs do not work well.

With more LDL in the bloodstream there is more LDL damaged by toxins, free glucose and oxygen free radicals. This is where macrophages come in.

Normally, naturalized serum vitamin D up-regulates macrophages. When the biological economy is running fine the macrophage garbage collection teams run full steam with half empty garbage trucks. This keeps the serum free of damaged LDL cholesterol. When there is a downturn in the vitamin D economy the body lays off macrophage garbage teams. The remaining macrophages have to do double and triple duty in clearing damaged LDL cholesterol. The macrophages become overloaded, break down and park along artery walls resulting in plaques (foam cell roadblocks).

HDL cholesterol is also a back up for macrophages. HDL will attempt to unload overloaded macrophages of excess cholesterol and put the investment bacl into vitamin D production. This is one of the reasons HDL is known as good cholesterol.

Normally, naturalized serum vitamin D up-regulates hepatic lipase. Hepatic lipase chops up triglycerides and clears them from the serum. Triglycerides are key to storing fat. In nature there is a lot of vitamin D in summer due to skin exposed to UVB, food is not short in summer and fat reserves are not needed, so when there is plenty of vitamin D there is plenty of hepatic lipase because fat is not needed. When the vitamin D economy downturns the hepatic lipase factories slow down hepatic lipase production and serum triglycerides go up with the lack of hepatic lipase to chop up the triglycerides. This lack of vitamin D tells the body it is winter time and time to store excess energy as fat because food is short in winter. In a bad vitamin D economy excess triglycerides would build up reserves by storing fat. In a good vitamin D economy there is no need to store fat.

So in vitamin D deficiency LDL goes up, macrophages go down, HDL goes down, hepatic lipase goes down and triglycerides go up, and fat storage goes up. All bad for heart health.

In a replete vitamin D biology LDL goes down, macrophges go up, HDL goes up, hepatic lipase goes up and triglycerides go down, fat storage goes down. All good for heart health

This represents an economy based on the tissues demand for a fair trade of vitamin D in exchange for tissue produced HDL cholesterol. When you look at biology like an economy based on fair trade it is easy to understand.

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