|Some butter on top of the broccoli would allow for the assimilation of the absorption of the 101.6μg vitamin K |
623IU vitamin A (various).
In view of the fact that the answers to (a) and be are not necessarily identical for all four vitamins of interest, it appears sensible to tackle them one after the other.
AStarting with vitamin A and the various forms of carotenoids, we can already confirm that (a), i.e. the assumption that we need dietary fats to optimally absorb vitamin A is correct. As Karin van het Hof and her colleagues point out, the "amount of dietary fat required to ensure carotenoid absorption [does yet] seem low (∼3–5 g per meal), although it depends on the physicochemical characteristics of the carotenoids ingested." (van het Hof. 2000) In spite of the fact that 5g of fat are not exactly much, the classic uncooked vegetarian orthorexic salad often comes with a total of only 5g of fat of which 95% remain at the bottom of the salad bowl. If that sounds like your favorite dish, you should be aware that you are risking that all the good beta- and other carotenoids in the salad will pass right through.
|Red Palm Oil is an excellent carotene source that comes with tons of fat for optimal absorption | learn more|
|Figure 1: Changes in hepatic vitamin A (retinol) and carotenoid stores in gerbils after 14 days on high fat (30%) vs. low fat (10%) diet (Deming. 2000)|
Interestingly enough, the provision of the fat blocker Orlistat reduces the absorption of vitamin A only insignificantly, as a 1996 paper by Angela T. Melia, Susan G. Koss‐Twardy, and Jianguo Zhi would suggest (Melia. 1996).
EWhich takes us right to vitamin E, the absoprtion which is - in spite of being "blocked" by the fat blocker orlistat (Melia. 1996) - less susceptible to the absence of dietary fat than you may think. Annet JC Roodenburg, Rianne Leenen, Karin H van het Hof, Jan A Weststrate, and Lilian BM Tijburg do in fact argue that the optimal intake of vitamin E requires only "a limited amount" of dietary fat (Roodenburg. 2000).
|Figure 2: Vitamin E serum levels after 7 days on control (low fat, 3g) or high(er) fat (36g) diet with and without supplemental vitamin E (Roodenburg. 2000)|
If you take a look at the high prevalence of vitamin E dieficiency among the fat (and PUFA) "loving", or at least eating, majority of Americans, it does yet become obvious that a lack of dietary fat is not just theoretically, but also practically not exactly the #1 reason you may become deficient in tocopherols and -trienols. That the latter is an increased demand due to chronic inflammation and the (over-)consumption of exactly those PUFAs that come with a shitload of vitamin E in nature, for a reason would yet be a topic for another SuppVersity article and thus something we will skip to fast forward to ...
K...Vitamin K, obviously. Vitamin K is a relative newcomer to the public's understanding of the alphabet soup. Aside from being it a good tool to rip customers vitamin K, or rather K1 (plant sources) and K2 (animal sources) are thus also the only fat soluble vitamins not everyone knows. The fact that the amount of phylloquinone (K1) that makes it into your blood stream is ~70% reduced if you eat your spinach without fat (Gijsbers. 1996).
And if we take the results researchers from the Gifu University School of Medicine present in a 1996 paper in the Journal of Pharmacological Sciences, as a reference, the amount of fat you need to optimally absorb your K2 (menaquinones), is not exactly low.
|Figure 3: For optimal absorption of K2, there has got to be a huge amount of fat in the meal - but who wonders. K2 comes with a high amount of fat (Uematsu. 1996)|
That's a pity, 'cause a high intake of vitamin K (menaquinone from animal sources) has been associated with a 27% reduced risk of developing heart disease (Geleijnse. 2004), an ailment of which many still believe that it was brought about by the fat they need to optimally absorb their vitamin K.
DFor vitamin D, our last "V" on the list, things look differently. For one, everybody knows about this miracle vitamin and for two, it may be "fat soluble", but the amount of fat that's required to optimally absorb it turned out to be much lower than previously thought (see "A Fat D-Ficiency! Do You Really Need More Vitamin D or Simply More Fatty Foods? Study Shows, Even 50.000 IU of Vitamin D3 Useless, When You Ingest It Without Fat. " | read more).
Actually you could argue that it's not fat, but cholesterol that should be essential for optimal D levels. It's not necessary to absorb supplements you should not be taking, but rather as a raw material that's used to produce vitamin D in the skin, once the latter is exposed to the sun. The allegedly logical assumption that statins which lower the production of endogenous (=your body's own) cholesterol would lower vitamin D levels, however, has been refuted in study investigating the effects of fluvastatin and rosuvastatin, of which the latter actually increased the 25-OHD levels (probably due to anti-inflammatory effects and a reduced use of vitamin D as an acute phase reactant | learn more)In fact, Niramitmahapanya et al. found in 2011 that it's not necessarily a high amount, but rather the right type of fat that determines if and how much of the vitamin D you take in capsule form or find in comparably low amounts in your foods that determines how much of the vitamin D actually makes it into your bloodstream:
"The change in plasma 25OHD (nanograms per milliliter) during vitamin D supplementation was positively associated with MUFA, (β = 0.94; P = 0.016), negatively associated with PUFA, (β = −0.93; P = 0.038), and positively associated with the MUFA/PUFA ratio (β = 6.46; P = 0.014)."In plain English this means, that the "good" seed and vegetable oils with their high PUFA content will effectively inhibit the absorption of vitamin D - an observation that adds to the many reasons the modern sedentary, sun-avoiding, sun-screen using, soybean oil (MUFA:PUFA = 0.4) guzzling American is low in or quasi devoid of vitamin D.
|Figure 4: 25(OH)D levels of 30 healthy men and women after ingestion of 50.000IU vitamin D3 supplement in conjunction with a normal or low fat breakfast (Raimundo. 2011)|
How much fat, exactly you would need to make the most of dietary and supplemental vitamin D, on the other hand, is still not known. The previously mentioned data from the study by Raimondo et al. (see Figure 4, to the right) I wrote about in "A Fat D-Ficiency" is obviously still valid. The extremely high amount of vitamin D (50,000IU!) could yet require a correspondingly high amount of fat to be optimally absorbed and the fact that the fat in the study came from a "vegetable margarine" with an undisclosed ratio of MUFA:PUFA does not make the real-world effects any more predictable.
- Chitchumroonchokchai, Chureeporn, et al. "Dietary fats with increased ratio of unsaturated to saturated fatty acids enhance absorption of carotenoid and vitamin E by increasing both efficiency of micellarization and lipoprotein secretion." FASEB J 24 (2010): 539-3.
- Deming, Denise M., et al. "Amount of dietary fat and type of soluble fiber independently modulate postabsorptive conversion of β-carotene to vitamin A in Mongolian gerbils." The Journal of nutrition 130.11 (2000): 2789-2796.
- Geleijnse, Johanna M., et al. "Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study." The Journal of nutrition 134.11 (2004): 3100-3105.
- Gijsbers, Birgit LMG, Kon-Siong G. Jie, and Cees Vermeer. "Effect of food composition on vitamin K absorption in human volunteers." British Journal of Nutrition 76.02 (1996): 223-229.
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- Jayarajan, P., Vinodini Reddy, and M. Mohanram. "Effect of dietary fat on absorption of β carotene from green leafy vegetables in children." Indian journal of medical research 137.5 (2013).
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- Lakshman, M. R., et al. "The effects of dietary taurocholate, fat, protein, and carbohydrate on the distribution and fate of dietary β‐carotene in ferrets." (1996): 49-61.
- Melia, Angela T., Susan G. Koss‐Twardy, and Jianguo Zhi. "The effect of orlistat, an inhibitor of dietary fat absorption, on the absorption of vitamins A and E in healthy volunteers." The Journal of Clinical Pharmacology 36.7 (1996): 647-653.
- van het Hof, Karin H., et al. "Dietary factors that affect the bioavailability of carotenoids." The Journal of nutrition 130.3 (2000): 503-506.
- Raimundo, Fabiana Viegas, et al. "Effect of high-versus low-fat meal on serum 25-hydroxyvitamin D levels after a single oral dose of vitamin D: a single-blind, parallel, randomized trial." International journal of endocrinology 2011 (2011).
- Ribaya‐Mercado, Judy D. "Influence of Dietary Fat on β‐Carotene Absorption and Bioconversion into Vitamin A." Nutrition reviews 60.4 (2002): 104-110.
- Roodenburg, Annet JC, et al. "Amount of fat in the diet affects bioavailability of lutein esters but not of α-carotene, β-carotene, and vitamin E in humans." The American journal of clinical nutrition 71.5 (2000): 1187-1193.
- Uematsu, Toshihiko, et al. "Effect of dietary fat content on oral bioavailability of menatetrenone in humans." Journal of pharmaceutical sciences 85.9 (1996): 1012-1016.