We have been working through nutrient pairings: calcium and vitamin D, iron and vitamin C, magnesium and vitamin D. This week closes the loop with the pairing that underpins a great deal of everyday eating: fat, and the four fat-soluble vitamins. Here is the full picture, including what each vitamin does, where to find it, and how to build the pairing into real meals.
Meet the four
Vitamins A, D, E and K are the fat-soluble vitamins. Each does distinct and important work, and each needs dietary fat to be absorbed.
Vitamin A supports vision, immune function, and skin. It comes ready-made in animal foods like liver, eggs and dairy, and as beta-carotene, which your body converts to vitamin A, in orange and dark green vegetables: carrots, sweet potato, pumpkin, spinach, kale.
Vitamin D supports calcium absorption and bone health, immune function, and muscle strength. Oily fish is the standout food source, with smaller amounts in egg yolks and UV-exposed mushrooms, and sensible sun exposure remaining the body's main source.
Vitamin E is an antioxidant that helps protect your cells. It is found in nuts, seeds, and plant oils, along with leafy greens and avocado.
Vitamin K is essential for blood clotting and plays a genuine role in bone health, working alongside vitamin D and calcium. It is concentrated in leafy green vegetables: kale, spinach, silverbeet, broccoli.
Notice how often these vitamins live in vegetables that contain little or no fat of their own. That is precisely why the pairing matters. The vitamin is there; the fat has to come from somewhere on the plate.
The pairing, built into meals
Bringing fat and these vitamins together is genuinely easy. A few examples that do it well.
A leafy green salad with an extra virgin olive oil and lemon dressing, so the vitamin K and E in the greens have the fat they need to absorb. Roasted carrots and sweet potato tossed in olive oil, unlocking their beta-carotene. Tomatoes with avocado or a drizzle of good oil, since the antioxidant lycopene in tomatoes is fat-soluble too. Sauteed greens finished with a splash of oil or a knob of butter. A piece of oily fish with a side of greens, which brings vitamin D and its fat together and adds fat for the greens beside it. Eggs, which conveniently carry their own fat alongside their vitamins A and D.
A simple rule of thumb
If a meal is built around vegetables, make sure there is a source of fat somewhere on the plate. Olive oil, avocado, nuts, seeds, a little dairy or butter, or the fat that comes with fish or eggs. It does not take much, a drizzle or a handful is plenty, and it transforms how much of the meal your body actually uses.
Which fats, and why it matters
The fats worth building meals around are the unsaturated ones: extra virgin olive oil, avocado, nuts, seeds, and the fats in oily fish. These carry the strongest evidence for health, particularly heart health, where replacing some saturated fat with unsaturated fat is consistently associated with better outcomes. For the fuller picture on this, see our guide to which fats to reach for.
Saturated fats, in butter, cheese and good-quality meat, are fine in moderation. The science here has grown more nuanced than the old blanket warnings suggested, and the form the fat comes in matters, whole foods rather than ultra-processed ones. Industrial trans fats are the genuine exception worth avoiding. Worth knowing: unlike the US, UK, EU and Canada, Australia does not yet regulate them or require them on the label, so leaning away from deep-fried fast food and long-life commercial baked goods is the reliable way to sidestep them here.
So the fat you add to unlock your vegetables is doing two good things at once: enabling absorption of the fat-soluble vitamins, and, if you choose mostly unsaturated sources, contributing to your health in its own right.
Why this matters more with age
Two of these vitamins, D and K, work together with calcium to support bone health, which becomes more important for women through perimenopause and after menopause as oestrogen declines and bone density changes. This is the same reason calcium and vitamin D matter so much together. Getting these fat-soluble vitamins adequately absorbed, by eating them with a little fat, is one more small lever that supports bone health over the long term.
The takeaway: Vitamins A, D, E and K each do important work, and each needs dietary fat to absorb. They live largely in vegetables that carry little fat of their own, so the fix is to always include a fat source on a vegetable-based plate. Reach mostly for unsaturated fats like olive oil, avocado, nuts and seeds, and you support both absorption and your wider health at once.