Knolle hat geschrieben: zum Beitrag navigieren3. Jul 2024, 18:39
Wie viel Vitamin D Tropfen und Omega 3 muss man denn nehmen, damit die fettlöslichen Vitamine genug Fett für die Aufnahme haben?
Bzgl. Fettminimumintakes wissen wir allgemein relativ wenig.
https://www.strongerbyscience.com/dietary-fat/
Fat-soluble vitamin absorption
If you thought this section would bring a precise target with more clarity than the previous section, brace for disappointment. In lieu of a massive literature review, I’ll save you some time and provide a simple summary: vitamin absorption is complicated. We see all sorts of interactions among micronutrients, such that some are absorbed less in the presence of certain micronutrients, but absorbed more in the presence of others. Based on a combination of biochemistry and intestinal physiology, we know that dietary fat should facilitate the absorption of fat-soluble vitamins (which are vitamins A, D, E, and K). However, when it comes to the research exploring exactly how much it matters and exactly how much dietary fat is needed (and when it should be ingested), the findings are all over the place.
For example, one study found that short-term vitamin D absorption was improved by a low-fat meal (11g) rather than no meal or a high-fat meal (35g), but it didn’t make a big impact on long-term vitamin D levels (5). Some studies have indicated that the fat content of a meal meaningfully impacts vitamin E absorption (6), while other studies find no substantial impact (7). It gets even messier when branching out from single-meal absorption to longer time scales (several months) when assessing dietary fat intake and adequacy of fat-soluble vitamins, because fat-soluble vitamins can be stored in body fat and other tissues for later use. As a result, a person’s circulating levels of a fat-soluble vitamin aren’t necessarily reflective of their recent dietary habits. We know that medical conditions involving fat malabsorption considerably increase the risk of fat-soluble vitamin deficiencies (8), so we know (by extension) that a zero-fat diet would not be suitable for enabling adequate absorption. However, when it comes to supporting fat-soluble vitamin absorption, a clear and concise daily minimum fat target eludes us.
The most common recommendation is to aim for at least 10% of calories coming from dietary fat in order to support fat-soluble vitamin absorption (9). That amounts to 11 g/day for a 1,000-kcal diet, 22 g/day for a 2,000-kcal diet, and 33 g/day for a 3,000-kcal diet. This is a great example of why percentage-based dietary recommendations have some pretty big limitations – I don’t believe vitamin needs go down when you decide to cut your calories, but that’s an unspoken assumption of any percentage-based recommendation in this scenario. People who make percentage-based recommendations generally assume that you’re eating somewhere around 2,000 to 2,500 kcal/day, so we can probably reframe this 10% of total energy target as 22-28 g/day of fat intake, give or take. In the interest of using round numbers that are easier to remember, we can call this 20-30 g/day – after all, what’s the harm in rounding an inherently imprecise number?
