The importance of Vitamin A

Dear Dr. Deena,
I hear so much about taking Vitamins daily. Can you tell more about Vitamin A?
JJ


Vitamin A is important for proper functioning of our immune system and the maintenance of healthy skin, bone and teeth. Vitamin A is essential for our vision (especially during the night when light is dim), since it is the main component of a protein called rhodopsin (which helps our eye form images at low light intensities).

Who Is At Risk for Vitamin A Deficiency?

Vitamin A deficiency is quite rare in the USA, but is quite common in underdeveloped countries in the world. The most obvious symptom of Vitamin A deficiency is called "xerophthalmia" or night blindness. 

Some of those at risk for Vitamin A deficiency include:

-Those suffering from poor nutrition due to limited access to foods containing Vitamin A

-Those with diseases effecting the pancreas like Cystic Fibrosis, pancreatic insufficiency, chronic pancreatitis, pancreatic cancer, etc.
The pancreas releases enzymes that help break down fats, allowing for improved absorption in the intestines. Vitamin A is composed of fats. If the pancreas is not functioning properly, Vitamin A cannot be broken down and absorbed appropriately.

-Those with diseases effecting the gall bladder like Choledocholithiasis (or obstruction of the bile duct), Primary Sclerosing Cholangitis, Cholangiocarcinoma (gall bladder cancer), etc.

The gall bladder releases a substance called bile which helps aid in the absorption of fats, such as Vitamin A. If the gall bladder is not functioning properly, Vitamin A cannot be absorbed by the intestines.

-Those with diseases effecting the intestine like patients who have undergone surgical resection of the intestines, those with Inflammatory Bowel Disease, Celiac Disease, etc.

Fats, like Vitamin A, are absorbed in the intestine. If the intestines are not functioning properly, Vitamin A cannot be absorbed appropriately.

Sources of Vitamin A

Sources of vitamin A are highest in liver and fish oils. According to the Institute of Medicine - "the top food sources of vitamin A in the U.S. diet include dairy products, liver, fish, and fortified cereals; the top sources of provitamin A (a precursor to vitamin A formation) include carrots, broccoli, cantaloupe, and squash ."

Beta carotenes, found in plant products, are converted to Vitamin A in our body. 
Foods high in beta carotenes include:
-Bright yellow and orange fruits such as cantaloupe, pink grapefruit, and apricots
-Carrots, pumpkin, sweet potatoes, and winter squash
- Leafy vegetables like broccoli and spinach

Recommended Doses of Vitamin A

According to the The Food and Nutrition Board of the Institute of Medicine:

The Recommended Dietary Allowance (RDA) for vitamins is how much of each vitamin most people should get each day. The RDA for vitamins may be used as goals for each person.

Children (RDA)

1 - 3 years: 300 mcg/day

4 - 8 years: 400 mcg/day

9 - 13 years: 600 mcg/day

Adolescents and Adults (RDA)

Males age 14 and older: 900 mcg/day

Females age 14 and older: 700 mcg/day

How much of each vitamin you need depends on your age and gender. Other factors, such as pregnancy and your underlying health, are also important.

Too much Vitamin A can lead to a Vitamin A toxicity, which can lead to liver failure, kidney damage, brain swelling and ultimately death. This is why it is important to ask your doctor what dose is best for you. 
 
True or false:
 Eating too many carrots can turn your skin orange.

Answer: True!


This condition is called "carotenemia" and it is caused by the excessive intake of carrots or other vegetables which increase the levels of carotenes in the blood. This is a harmless condition and is usually seen in lighter-skinned individuals, infants, and young children. 

These "Carotenoids" are deposited in the thickest layer of the skin called the stratum corneum. This is why the color change is most notable in the areas where skin is the thickest:  palms, soles of feet, knees, and nasolabial folds.  

As mentioned before this condition is harmless, as the body will regulate the levels of carotenes. Those with carotenemia will get better slowly over weeks to months depending on how much carotene was consumed.   

Here is a photo of the palm of a patient with carotenemia compared to a normal palm:

I hope you found this information helpful! 

Please feel free to leave comments below, and email me at DoctorDeenaMD@gmail.com with any questions or tips that you would like me to discuss!

**PLEASE REMEMBER IF YOU HAVE ANY QUESTIONS OR CONCERNS ABOUT YOUR HEALTH AND/OR BEFORE STARTING OR STOPPING ANY TREATMENT OR ACTING UPON INFORMATION CONTAINED ON THE SITE, YOU SHOULD CONTACT YOUR OWN PHYSICIAN OR HEALTH-CARE PROVIDER**

All About the Flu!

Dear Dr. Deena,

What is the flu and how do I avoid it?

Thanks,

Rob

Hi Rob. Thanks for your question which is just in time for Flu season!

Flu is caused by a virus known as the Influenza virus. There are many different types of Influenza viruses. The Influenza vaccine protects us against the most common types of Influenza during that particular season -- but there is always a possibility of catching a strain that is not covered by the vaccine.

The flu virus is mainly spread through respiratory droplets in the air (via sneezing or coughing), but can also occur after touching surfaces which have been contaminated with the virus (mainly touching the contaminated surface with your hand and then touching one's eye, mouth, or nose). The reason the flu is so common in the wintertime is because the air is drier, allowing the virus particles to stay in the air much longer. When the air is humid, these virus particles are surrounded by water which increase its weight and cause it to drop down to the surface more quickly. Studies have shown that human influenza viruses generally can survive on surfaces between 2 and 8 hours. This is the reason why the flu is much less common in the more humid, warmer parts the world and more prevalent during certain times of the year.  The flu is also more common during the wintertime as more people stay indoors, which means you are more likely to come in contact with the germs of a sick individual. 

Common flu-like symptoms include runny nose, coughing, sneezing, sore throat, muscle weakness, chills and feeling tired. These symptoms usually get worse over 2-3 days, and then slowly get better over days to weeks! Generally those with underlying lung disease or poor immune status (patients on chemotherapy, people with HIV, etc,) take longer to recover from the flu.

Steps that can be taken to avoid the flu:
-Avoid close contact with sick people
-Keep at least an arm's distance away from sick contacts
-While sick, avoid close contact with others
-Cover your nose and mouth with a tissue when you need to cough or sneeze
-Wash your hands often with soap and water
-Wipe up all contaminated surfaces with soap and water or other disinfectants
-Get vaccinated. Click here to read who should get vaccinated.


Hope this helps! 

Please feel free to email questions to DoctorDeenaMD@gmail.com and share your comments below!

**PLEASE REMEMBER IF YOU HAVE ANY QUESTIONS OR CONCERNS ABOUT YOUR HEALTH AND/OR BEFORE STARTING OR STOPPING ANY TREATMENT OR ACTING UPON INFORMATION CONTAINED ON THE SITE, YOU SHOULD CONTACT YOUR OWN PHYSICIAN OR HEALTH-CARE PROVIDER**


Interesting Fact:
A single sneeze can release over 40,000 droplets. It only takes exposure to a FEW of these droplets to be infected by the flu!