Vitamin A, Our Forgotten Hero
Vitamin A rarely gets a mention in health journals - and if it does, it is often vilified as being dangerous and toxic - which it is - in large amounts! Because it is a fat soluble vitamin, it can build up in your liver over time or may even affect your unborn baby if you take too much in pregnancy, so ( as we always suggest), get some professional advise if you want to supplement with any nutrient.
So I thought that I would write a little something on how vital this nutrient is to our body and particular to our thyroid health:
The term Vitamin A sounds like it is one nutrient, but, it is actually a collection of (mostly) fat soluble retinoids, that are biologically active compounds occurring naturally in both plant and animal tissue.
Vitamin A from animal sources is fat soluble, in the form of retinoic acid, retinal and retinol. Plant sources are usually in the form of "provitamin A" compounds like carotenoids, which need to be converted by the body to retinoids. These are water soluble.
"Enough of the boring science" I here you say.... so, why do we need them?? and what is Vitamin A good for??
VitaminA plays a vital role in bone growth, reproduction, immunity, gut function, skin health, thyroid function and, no surprise given the name, eye health (retina... retinoids... get it??). In fact just increasing your consumption of Beta carotene-rich foods long term can actually PREVENT you developing age-related macular degeneration - a leading cause of blindness for the elderly. But we are talking long term here - this prospective cohort study sampled over 100,000 individuals over the age of 50 and discovered that increased carotenoid intake over 20 years led to higher visual acuity and an up to 40% reduction in cases of advanced age-related macular degeneration! Now if that was a pharmaceutical drug, this study would have been splashed all over the media. But since it is a humble vitamin, only nerdy nutritionists seem to know about it!!
Carotenoids need to be converted by the body into retinoids before they can be utilised, and this can pose a few issues - if we are healthy, the conversion requires 6 units of carotenoids to convert to one unit of retinol - it is an energy expensive and difficult process, that can be affected by poor thyroid function, diabetes and blood sugar issues, low fat diets, and compromised gall bladder andliver function and (as always) poor digestion.
The animal sources are the most bio-available (i.e. easiest for the body to utilise) true retinoid food sources include; cod liver oil, pate, liver such as lambs' fry, egg yolks, butter (from grass fed cows), fish, beef, and chicken.
Betacarotene is plentiful in vegetable sources such as carrots, oranges, paw paw, sweet potato and pumpkin. This form of vitamin A cannot be utilised by the body so first needs to be converted to its retinoid form as explained above, which requires a healthy gut, liver and plentiful active thyroid hormones (that's the T3 form). Ironically, you need retinoid to convert your inactive thyroid hormone (Thyroxine or T4) to the active version (triiodothyronine or T3) So if you have a thyroid problem, you are probably not converting your betacarotene effectively. Peach or yellow coloured palms are a bit of a clue that this is happening ( unless you eats loads of orange veggies!). If you suspect that this may be you - seek the guidance of a health care professional who is knowledgeable in this area.
So which IS the best form of Vitamin A to have?
As always it is optimal to have a balance. (Unless you have a thyroid problem, then you may need some supplementation and/or concentrate on the animal sources).
Eat the rainbow - including orange and red fruits and veggies as well as those animal sources mentioned above. It's also OK if you don't like liver (or pate!): Eggs are one of the best sources and as long as you eat (TRUE) free-range eggs, you will be getting a perfect combo of omega 3 and omega 6 fats!
So go and enjoy your daily dose of vitamin A. Eat those first 3 bands of the rainbow! Red, Orange, Yellow and be well :)
Alexandra ~ naturopath and nutritionist~
With thanks to Katrina Parsons, naturopath, who also scribed some of this post.