Vitamin D and your Genetic make-up

Vitamin D

When looking at our genetic make-up, there are some people who have a CYP27B1 gene mutation which affects how your body uptakes Vitamin D. The Vitamin D deficiency shows in the genetic breaks of VDDR1 and VDDR2. FYI: If you have one or both of these genetic breaks, science has found that the intake of caffeine will block the body’s ability to absorb Vitamin D due to these mutations.
“VDDR1 and VDDR2 are characterized by low levels of the minerals calcium (hypocalcemia) and phosphate (hypophosphatemia), which are essential for the normal formation of bones and teeth. Affected individuals also have high levels of a hormone involved in regulating calcium levels called parathyroid hormone (PTH), which leads to a condition called secondary hyperparathyroidism. The two forms of vitamin D-dependent rickets can be distinguished by blood levels of a hormone called calcitriol, which is the active form of vitamin D; individuals with VDDR1 have abnormally low levels of calcitriol and individuals with VDDR2 have abnormally high levels.
Hair loss (alopecia) can occur in VDDR2, although not everyone with this form of the condition has alopecia. Affected individuals can have sparse or patchy hair or no hair at all on their heads. Some affected individuals are missing body hair as well.
CYP27B1 gene mutations cause VDDR1, and VDR gene mutations cause VDDR2. Both genes are involved in the body’s response to vitamin D, an important vitamin that can be can be acquired from foods in the diet or made by the body with the help of sunlight. Vitamin D helps maintain the proper balance of several minerals in the body, including calcium and phosphate. One of vitamin D’s major roles is to control the absorption of calcium and phosphate from the intestines into the bloodstream.
The CYP27B1 gene provides instructions for making an enzyme called 1-alpha-hydroxylase (1α-hydroxylase). This enzyme carries out the final reaction to convert vitamin D to its active form, calcitriol. Once converted, calcitriol attaches (binds) to a protein called vitamin D receptor (VDR), which is produced from the VDR gene. The resulting calcitriol-VDR complex then binds to particular regions of DNA and regulates the activity of vitamin D-responsive genes. By turning these genes on or off, VDR helps control the absorption of calcium and phosphate and other processes that regulate calcium levels in the body. VDR is also involved in hair growth through a process that does not require calcitriol binding.
Mutations in either of these genes prevent the body from responding to vitamin D. CYP27B1 gene mutations reduce or eliminate 1α-hydroxylase activity, which means vitamin D is not converted to its active form. The absence of calcitriol means vitamin D-responsive genes are not turned on (activated). VDR gene mutations alter the vitamin D receptor so that it cannot regulate gene activity, regardless of the presence of calcitriol in the body; often the altered receptor cannot interact with calcitriol or with DNA.
Without activation of vitamin D-responsive genes, absorption of calcium and phosphate falls, leading to hypocalcemia and hypophosphatemia. The lack of calcium and phosphate slows the deposition of these minerals in developing bones (bone mineralization), which leads to soft, weak bones and other features of vitamin D-dependent rickets. Low levels of calcium stimulate production of PTH, resulting in secondary hyperparathyroidism; hypocalcemia can also cause muscle weakness and seizures in individuals with vitamin D-dependent rickets. Certain abnormalities in the VDR protein also impair hair growth, causing alopecia in some people with VDDR2.” Source: Genetic Home Reference

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s