What is Cholesterol?

Cholesterol is a waxy, yellowish substance produced by the liver.  It is technically not a fat. It is a normal and necessary part of most body tissues, including cell membranes, the brain, nervous system, liver and the blood.  Cholesterol does not dissolve in blood and hence needs to be transported through the blood stream by means of a carrier called “Lipoproteins”

What is good cholesterol and bad cholesterol?

There are two major types of lipoproteins that carry cholesterol in the blood:

High-density lipoprotein (HDL)

Low-density lipoprotein (LDL)

HDL works to rid the body of excess cholesterol, thereby reducing the amount of cholesterol that is deposited on the blood-vessel walls, it is sometimes called “good cholesterol”.

LDL carries cholesterol from the liver to other body tissues, depositing excess cholesterol on the walls of arteries, thus clogging the arteries- a condition called artherosclerosis – and leads to the development of heart disease and stroke. Hence LDL is termed as “bad cholesterol”.

What is acceptable cholesterol level?

For a long time it was considered that a total cholesterol level of less than 200 mg/dL was safe and desirable. However with new research findings, the threshold levels are getting redefined. For instance, currently LDL cholesterol at <100 is considered desirable. This is a significant reduction compared to earlier acceptable levels of 120-130.  Similarly HDL levels >60 are considered ideal.  HDL < 35mg/dL, is cause enough for alarm.  Apart from the individual values, one also needs to look at the ratio of  HDL (good cholesterol) to LDL (bad cholesterol). This is more important in determining a person’s risk for heart disease and stroke.

The significance of vitamin D testing in maintaining good health has received unprecedented attention in recent times. Usually adequate levels of vitamin D in the human body is associated with good skeletal health and deficiency with bone metabolism abnormalities. Bone deformities in children from rickets are caused by low levels of vitamin D. Abnormalities in calcium and phosphorous levels in the body are also linked to low levels of vitamin D. In addition to this, studies have shown Vitamin D deficiency to have some linkages to certain types of cancers, diabetes mellitus, multiple sclerosis, autoimmune disease, cardiovascular disease, crohn’s disease and other inflammatory bowel disorders. These findings appear to be responsible for the recent increase in vitamin D testing.

What is Vitamin D?

Vitamin D is a group of fat soluble secosteroids that act as precursors to biologically active 1,25-dihydroxy vitamin D. It refers to both the D2 and D3 forms of these compound. A secosteroid is a molecule similar to steroid but with a broken formation. Vitamin D is unique compared to other vitamins because it both a pro hormone and a vitamin that the body synthesis with exposure to adequate sun light.

Serum 25-hydroxy vitamin D is the test of choice to assess a patient’s vitamin D levels. It is preferred because it reflects the precursor levels of vitamin D.

Current assays measure total vitamin D i.e. 25-hydroxy vitamin D

What is the recommended level of vitamin D?

The recommended blood levels of vitamin D – is more than 30ng/ml