While the
USDA nutrient database (search 'milk') indicates non-added vitamin A milk products, I've yet discovered any fluid milk products -- fat-free, 1%, 2%, whole -- on local store shelves
without vitamin A added (from casual nutrition facts checks when shopping).
Moreover, when I've come across no milk nutrition label specifying its added vitamin A as "beta-carotene", I presume all milks are vitamin A fortified 100% retinol. That milk labels would mention beta-carotene content, if there were any, I base on a dairy product that does just that: Smart Balance Omega Light "spread". Its label reads, for a standard 1 Tbsp serving:
"Vitamin A 10% (18% beta-carotene)"I read that as: 'Of the vitamin A content in a Tbsp of this product supplying 10% DV, 18% is beta-carotene, 82% is retinol.' Now, that's in a "buttery spread" product
designed to be "healthier" than competitors (e.g. Omega-3 ALA 20% DV, Omega-3 EPA,DHA 20% DV; vitamin D 50% DV (1997 standards); oils--soybean,palm fruit,flaxseed,fish,canola,oilve;non-hydrogenated). I would expect any less-specifically health-focused dairy product -- like
standard added-vitamin A milk and cheese (or non-dairy cereal) products -- to be 100% retinol-based.
From the Harvard School of Public Health:
source 1:
...Plus, dairy products can be high in saturated fat as well as retinol (vitamin A), which at high levels can paradoxically weaken bones.
source 2:
Vitamin A. Several studies have shown a correlation between high vitamin A intake and fracture risk. Some experts say it’s time to stop fortifying milk and
breakfast cereal with vitamin A, because the population is getting older and the prevalence of osteoporosis is increasing. Meanwhile, you should avoid multivitamins that contain 10,000 IU of vitamin A, which is twice the recommended daily intake of 5,000 IU — and many experts think that’s too much. Bear in mind that
the beta carotene in carrots and other vegetables is not a problem. It is far less biologically active than retinol, the form of vitamin A in many vitamin pills and fortified foods.
source 3 for food sources, RDA, etc
From what I gleaned shopping for 1/2-gal milk, the amount of vitamin A per 8 oz serving of milk ranges between 6% to 10% the Daily Value. (Again, I found none without added vitamin A.)
Most processed cheeses offer 4% DV of vitamin A, although I discovered a Borden's product that I consider a hazard to effective vitamin D metabolism and would avoid. Check it out:
Single serving examples:
Bayview Fat-Free Milk, 8oz: vitamin A
10% DV (vitamin A palmitate)
Smart Balance LF milk, 8 oz: vitamin A
10% DV (vitamin A palmitate)
Borden's American Singles cheese slice, "triple calcium": vitamin A
4% DV (vitamin A palmitate)
Borden's "Essentials": vitamin A
20% DV (vitamin A palmitate) (!!!)
Note: The terms "Vitamin A" and "Vitamin D" usually refers to the "active" form when professionals use them indiscriminately. However, without specificity the terms can also be causes of confusion, even amongst academics. Rheinhold Vieth devoted an entire
article to Vitamin D terminology:
Abstract
Official nutrition committee reports in both North America and Europe now state that Vitamin D is more of a hormone than a nutrient. These statements are wrong, and do not reflect the definitions of either vitamin or hormone. Researchers often compound the problem by referring to calcitriol or other deltanoids as “Vitamin D”. These things have serious consequences: (1) The literature is burdened by an ongoing confusion that presumes that the reader will somehow “know” what the writer refers to by “Vitamin D”. (2) Medical practitioners not familiar with the ambiguities administer Vitamin D inappropriately when calcitriol or a deltanoid analog would be correct, or vice versa. (3) Attempts to promote VitaminD nutrition are hindered by alarmist responses justifiably associated with the widespread administration of any hormone. VitaminD is a vitamin in the truest sense of the word, because “insufficient amounts in the diet may cause deficiency diseases”. The term, prohormone, is not relevant to the VitaminD system, but 25-hydroxy-VitaminD (calcidiol) is appropriately described as a prehormone, i.e. a glandular secretory product, having little or no inherent biologic potency, that is converted peripherally to an active hormone.
The
Daily Value for Vitamin A is 5000 IU.
1) Let's say a person ingests one glass of milk a day (10% DV, no other milk porducts) and 1 slice of Borden's 'American singles' cheese (4% DV):
500+200 IU == 700 IU
retinol.
2) Let's say a person ingests one glass of milk a day (no other milk porducts) and 1 slice of Borden's 'Essentials' cheese:
500+1000 IU == 1500 IU
retinol3) Let's say 1 glasss of milk plus 1/2 glass-equivalent in other milk products, and 3 slices of 'Essentials' cheese in a hoagie sandwich
750+ 3000 == 3750 IU
retinol (before even taking some daily multivitamin with 50% or 71% retinol)
Since Cannell commends Life Extension's reduction of retinol in its multivitamin to "only 500 IU" (a daily intake), presumably scenario 1 shouldn't be a great concern. But I'd consider the other two intakes of retinol -- i.e., from only a couple of dairy products (more daily exposure to other products, to be sure) -- to be risky "high". Remember, we're talking about
active vitamin A, not substrate beta-carotene. And while Dr. Cannell does specifically advise against cod liver oil -- for its very high 100% retinoic acid content in small servings -- I'm further concerned about another tidbit of information from him in his response to a mother of two autistic children, which might go unappreciated in the context of consumption of common dairy products like milk, cheese, etc:
...It may take years for the toxic amounts of vitamin A to be removed from their system because, unlike vitamin D, the body has no good system to remove vitamin A quickly.
In the above context, what concerns me is how cumulative might be retinol intakes, i.e., over multiple meals and multiple days? How efficiently is
active vitamin A used, depleted and/or evacuated? (I've read it's re-used.)
Although Dr. Cannell didn't specifically speak or warn about a process of cumulative build-up of
active Vitamin A, isn't there an implication of such in the phrase: "the body has no good system to remove vitamin A quickly"?
That's why I've become leary of dairy products with "4% DV" or "6% DV" or "10% DV" or "20% DV" vitamin A -- and such intakes would be apart from any multivitamin one might eventually take later (e.g., Centrum, 5000 IU vitamin A, 71% retinol). It would seem all too easy to
accumulate retinol throughout the day via dairy products, if I get the gist of Cannell's comment and extrapolate correctly. (Let me know, if I'm wrong.) I checked labels of 17 brands of multivitamins sold on a website: Only 4 offered 100% beta-carotene.
Vitamin D healthy metabolism and robust immune system require care with Vitamin A intake: retinol vs beta-carotene. It's intriguing, too, the same organ manages a perfect ratio of the active forms of the two vitamins (if allowed to do so)
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