Cholesterol is an oily fatty substance that is essential to the body for a number of reasons. First and foremost it is part of the body's repair mechanism, and helps to repair damaged cells. Without cholesterol, your body could not repair the daily damage that takes place, and would die. However, too much cholesterol can be almost as dangerous as too little, and we need to control, or manage, the level of cholesterol within our bodies. It is also used in the production of bile and for cell membranes.

Cholesterol is carried in the blood stream. Since it is an oil, it does not mix with water, and hence needs a carrier to transport it round the blood. There are basically two such carriers known as low density lipoprotein (LDL) and high density lipoprotein (HDL). The LDL is a sticky substance like tar, and the blood carries it to areas where a repair is needed, much like a road repair crew carrying tar. It deposits the tar where needed to repair the damage, and any excess is picked up by the more fluid HDL, and taken back to the liver where it is destroyed and excreted. The LDL is called ?bad cholesterol?, even though it does good things to your body, and the HDL is called ?good cholesterol? since it is destined for destruction.

The problem with LDL is that, over time, it will deposit so much cholesterol in your arteries that it will form a solid plaque that narrows and hardens them. This is called atherosclerosis, or ?hardening of the arteries? and is very dangerous when in the arteries of your heart or your brain. If a blood clot forms and is pumped into a narrow part of an artery, it can cause fatal heart attacks or strokes.

The answer is not to reduce your cholesterol to zero, but a level considered reasonable safe. That level is 130 mg/dl (milligrams per deciliter) for LDL and above 60 for HDL. You total cholesterol should not exceed 200, and in excess of 160 for LDL means that you are at a significantly higher risk of heart disease and a stroke.

Cholesterol is obtained from animal sources such as meat, eggs and dairy produce. However, all cholesterol does not enter your body in your diet. In fact your body does not need any dietary cholesterol since the majority of it is manufactured in your liver from trans and saturated fats. There are many vegetable sources of these fats, such as several vegetable oils, coconuts, cookies, donuts, French fries, margarines, crackers, popcorn and potato chips. That is only part of the list, so even vegans can have a high cholesterol level if they do not look at their diet.

It has been known for a long time that niacin, otherwise known as Vitamin B3 or nicotinic acid, can help the body to generate HDL. It is part of a normal diet, and helps the body covert carbohydrates to glucose which is then used for energy. It also helps maintain a healthy nervous system and digestive system, and is good for healthy skin, eyes and hair. However, if used in larger quantities it can help the liver to increase the HDL content of your body by as much as 35%.

HDL levels of 40 mg/dl for men and 50 for women are considered at risk, while above 60 is considered a healthy level. HDL removes LDL from the body and so niacin increases the proportion of good cholesterol in the body at the expense of the bad. It cannot, and should not, replace all the LDL though, since HDL has no effect in repairing body cells. In fact HDL is not really cholesterol at all in terms of any usable meaning of the word. It's like saying that vitamins in your urine are good vitamins, and those in your blood are bad vitamins, because although vitamins are needed for health, an excess of some vitamins can be very damaging.

So cholesterol is essential, but an excess can kill you over time. It is matter of balance and niacin can help to control that balance better than some drugs that are designed to prevent cholesterol being produced, period. That would be even more dangerous to you than over-production.

However, niacin alone is not the complete answer. You should also maintain a good diet that is low in saturated fats and trans fats. Unfortunately, trans fats are manufactured by hydrogenating vegetable oils to make them spreadable or solid, such as the vegetable shortenings used by industrial bakeries, so it is not easy to spot these in your ingredients list.

You should also eat a diet low in animal fats. Cut down on the burgers, fatty bacon and pork crackling. A high fiber diet also helps since soluble fiber tends to absorb LDLs and pass the out through the body. Plant sterols and stanols, such as found in brassicas, cocoa and saw palmetto, reduce the absorption of cholesterol into the body from the intestine. Some breads, meats and cereals are now having these materials artificially added for this reason. Drinks are also now available that contain high levels of plant stanols.

Although the use of high doses of niacin (up to 100 milligrams daily) is though to be safe, more evidence is still require for all uses. Doses of up to 1000mg can be taken for reducing cholesterol, but your doctor must be consulted in such cases. Pregnant women are advised to refer to their physician before using niacin, as should diabetics. Niacin supplements can cause what is known as a ?niacin flush? when your skin turns pinkish, and you will arm for about 15 minutes then it will go. You can get ?flushless niacin?, though the flush is good for the circulation.

Oral contraceptives can reduce the effectiveness of vitamin B3, so you should consult your doctor in this case. Also, the effect of statins in reducing cholesterol levels can be enhanced in the presence of niacin, so again your doctor should be consulted. An excessive reduction of cholesterol levels in your body could be harmful. You should also contact your doctor of you suffer from liver problems, stomach ulcers, gout or low blood pressure since high doses of niacin can aggravate these conditions.

Vitamin B3 is generally safe to take with other vitamins and it is generally a part of a Vitamin B complex supplement, and of multivitamin supplements. Very high doses of 1000 mg or more can lead to serious side effects, and anything above 500 mg should be taken only under medical supervision. Otherwise, niacin is an excellent way to reduce cholesterol levels, especially when taken with soluble dietary fiber.