COMPENDIUM ON FUNCTIONAL MEDICINE - Flipbook - Page 183
● When there are medical conditions that can impair vitamin A
absorption including cystic fibrosis, Crohn's disease, celiac
disease, or those who have had bariatric surgery.
Range
Units
Conventional
42.0-153.7 mcg/dL
Optimal / Functional
42.0-153.7 mcg/dL
Elevated liver enzymes may be seen on blood work as vitamin A is
stored in the liver and thus can affect it at high levels.
Vitamin D
This vitamin is important for keeping your bones and teeth strong
because it helps your body absorb calcium and phosphorus4the
key minerals they’re made of. Vitamin D also supports healthy
muscles, nerves, and a well-functioning immune system.
Low vitamin D can weaken your immune system and has been
linked to heart disease, cancer, and bone disorders like rickets
and osteoporosis.
The 25-hydroxyvitamin D test4often called the Calcidiol
test4measures the amount of 25(OH)D in the blood. This is the
main form of vitamin D circulating in the body and is considered
the most reliable marker for assessing overall vitamin D status.
When to use this test:
● For those who live in areas with limited sun exposure
experiencing bone pain, muscle weakness, fatigue, or mood
changes.
● When there are conditions like Crohn's disease, celiac
disease, or kidney/liver disease that can affect vitamin D
absorption or metabolism.
183
