Retinol Please!

What is Vitamin A?

Vitamin A is a fat-solube micronutrient in several foods. It helps in the general function in skin, eyes, hair, the immune system and in reproduction. Vitamin A is vital in vision more than anything else. It is especially essential to the prevention of nocturnal blindness. Simply eating carrots will not improve your nocturnal vision since carrots do not supply a fundamental "ingredient" for better vision. Carotenoids are needed for improving vision. Beta-carotene, the "ingredient" and a carotenoid, can form into vitamin A. Vitamin A is another term for retinol, because it produces the pigments in the retina of the eye. In order to have a well source of vitamin A for vision, you must know the different types of Vitamin A and its sources.

Types of Vitamin A

There are two types of vitamin A suppliers. The two types of Vitamin A are preformed vitamin A and provitamin A. Preformed vitamin A is the most beneficial form of vitamin A found in animal products such as meat, dairy, fish, etc. Red meats are usually high in cholesterol so the amount of intake should be moderate. In dietary supplements, it is in the form of retinyl acetate or retinyl palmitate. Preformed vitamin A is usually toxic in high levels from supplements and medicines and should be taken at a cautious level. High intakes can cause nausea, headaches, and possibly death. In women, if pregnant, high intakes of supplemented preformed vitamin A can cause birth defects.

Find out more about buying dietary supplements: http://ods.od.nih.gov/Health_Information/ODS_Frequently_Asked_Questions.aspx#Brands

 Meanwhile, provitamin A is found in plant-based products such as fruits and vegetables. The most important type of provitamin A is beta-carotene. Beta-carotene is one of many carotenoids and an antioxidant, which protects cells from free radicals that cause damage.

Beta-carotene food products may reduce the risk of cancer but is still not well supported and research is still in progress. Although, it can reduce the risk of LDL from saturated fatty acids in preformed vitamin A. Some sources of beta-carotene are carrots, cantaloupe, pink grapefruit, sweet potatoes, broccoli, and other green vegetables. Unlike preformed vitamin A, beta-carotene is not toxic and its levels of intake do not have to be monitored for health risks. It is better to search for multivitamins that contain beta-carotene instead of those that contain preformed vitamin A. However, too much beta-carotene in your diet can turn your skin yellow or orange. Now, if you do not get enough retinol then you can encounter vision problems and a probable need for glasses.

Find out more: http://www.medicalnewstoday.com/articles/252758.php


How Much Retinol Do I Need? 

Currently, there is no vitamin A deficiency in the United States. The RDA for males age 14 and older is 900 mcg/ day and for females age 14 and older is 700 mcg/day. Your health diet, age, gender, and environment are all factors for determining your recommended dietary allowance for vitamin A so consult your doctor for the best measured dose you require.

Table 1: Recommended Dietary Allowances (RDAs) for Vitamin A 

Age	Male	Female	Pregnancy	Lactation
0–6 months*	400 mcg RAE	400 mcg RAE
7–12 months*	500 mcg RAE	500 mcg RAE
1–3 years	300 mcg RAE	300 mcg RAE
4–8 years	400 mcg RAE	400 mcg RAE
9–13 years	600 mcg RAE	600 mcg RAE
14–18 years	900 mcg RAE	700 mcg RAE	750 mcg RAE	1,200 mcg RAE
19–50 years	900 mcg RAE	700 mcg RAE	770 mcg RAE	1,300 mcg RAE
51+ years	900 mcg RAE	700 mcg RAE

* Adequate Intake (AI), equivalent to the mean intake of vitamin A in healthy, breastfed infants.

(reference table from Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies)

( Summary of Vitamin A) 

Vitamin A Deficiency...briefly....spine shivers

Keratomalacia

Keratomalacia is a severe result of vitamin A deficiency. Early symptoms of this are poor vision at night and extreme dryness of the eyes. In some developing countries, it is caused by childhood blindness and inadequate nutrition. (more on: http://www.webmd.com/eye-health/keratomalacia )






References: 

• http://ods.od.nih.gov/factsheets/VitaminA-QuickFacts/
• http://www.nlm.nih.gov/medlineplus/ency/article/002400.htm
• http://www.hsph.harvard.edu/nutritionsource/vitamin-a/