Vitamin A 

What is it and why do we need it? 

Vitamin A is in the fat-soluble vitamin family (along with vitamin D,E and K) which have anti-inflammatory effects. Okay, cool. What is a fat-soluble vitamin? The fat-soluble vitamins, bind to fat in the stomach and are then stored in fatty tissues and the liver. These vitamins are not excreted readily, and when taken in excess, they can build up in the body and lead to unwanted, and potentially dangerous, adverse effects. Well, that doesn't make us want to eat them, right? Wrong. There are still so many important reasons why you need these vitamins and more specifically for this post, why you need vitamin A. 

Vitamin A is important for: 

• immune system function
  • essential for mucous membranes (examples include lips, mouth, nasal passages, middle ear, digestive tract lining, vagina and much more)
  • helps prevent Sjogren's disorder (affects 13% of the population, ten times as many women as men. About half of the patients also have rheumatoid arthritis or other connective tissue diseases, such as lupus)
• needed for a healthy pregnancy 
  • vitamin A is necessary for cell growth
• helps protect from cardiovascular cancer & disease
• growth & maintenance of skin
  • needed for collagen synthesis and formation of gum tissue
  • help prevent psoriasis and rosacea (digestive book p 390 + 398) 
• proper vision & eye function

Two forms of vitamin A

1. preformed and
2. provitamin A carotenoids. 

The human body converts beta carotene into vitamin A (retinol) - beta carotene is a precursor of vitamin A. Beta carotene in itself is not an essential nutrient, but vitamin A is. Plant food sources do not contain preformed vitamin A, but some do contain provitamin A carotenoid, which can be converted to retinol in your body. Carotenoids are the yellow-red pigments that give carrots, butternut squash, and cantaloupe their vibrant, deep orange color.

Vitamin A is also known as retinol and is actually a family of substances called retinoids that includes retinol, retinal, and retinoic acid. These are called preformed vitamin A because they are in a form that your body readily uses. Retinol is the most usable of the three forms and can be converted to both retinal and retinoic acid in your body for its various uses.

Preformed vitamin A is found only in foods from animal sources, such as liver and eggs, and is added to all processed milk.

Food Sources

Vitamin A can come from both plant and animal sources.

Plant foods rich in carotenoids (which most people convert to vitamin A) are all green, yellow and orange vegetables:

• carrots,
• pumpkin, 
• winter squash,
• dark green leafy vegetables and
• apricots... to name a few

Animal sources include liver, salmon, and whole milk. Vitamin A is also added to fortified cereals, is a part of most multivitamins, and is available as a stand-alone supplement. 

Should you supplement vitamin A?

Most people should not need to supplement with vitamin A along unless recommended by a doctor after having your vitamin levels checked. The recommended amount of vitamin a is 5,000UI of preformed vitamin A and up to 25,000UI carotenoids per day. 

Resources

• Digestive wellness book (citation coming)
• The real vitamin & mineral book (citation coming)
• https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
• https://www.pharmacytimes.com/publications/otc/2015/OTCGuide-2015/Vitamins-and-Minerals-Explained
• https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Sjogrens-Syndrome
•  https://www.sharecare.com/health/vitamin-a/vitamin_a_beta_carotene
• https://www.medicalnewstoday.com/articles/252758.php