Recent reporting by BBC News highlights growing evidence that ingredients like fats and spices can significantly improve the body’s ability to absorb vitamins. The reason lies in how digestion works.

Nutrients must first escape the physical structure of food, dissolve in digestive fluids, and then pass through the gut lining into the bloodstream. Many fail along the way.

Fat-soluble vitamins, such as A, D, E, and K, are especially dependent on this process. Without dietary fat, they simply cannot dissolve properly and are flushed out unused. “Oil-soluble vitamins don’t dissolve in water, so without fat they just pass straight through the gastrointestinal tract,” says David Julian McClements, professor of food science at the University of Massachusetts and a leading researcher in nutrient bioavailability.

McClements’ work shows that tiny fat droplets found in foods like milk, yoghurt, and olive oil form microscopic carriers, known as micelles that transport vitamins through the digestive system. In one study, people who ate salads with olive oil–based dressings absorbed far more carotenoids than those who ate the same vegetables without fat.

Then there’s black pepper. Beyond its flavour, it contains a compound that blocks intestinal transporters that would normally eject absorbed nutrients back into the gut. When McClements and his team added black pepper to meals, vitamin absorption increased even further.

For McClements, this discovery felt like déjà vu. While developing modern delivery systems for curcumin, a compound found in turmeric, his team realised they had recreated something ancient. Traditional “golden milk”, a blend of turmeric, milk, and black pepper, uses the same principles scientists now study in laboratories.
The takeaway is simple. Nutrition isn’t just about what you eat, but how you eat it.

A salad without dressing or vegetables cooked without fat may look healthy, but they could be leaving much of their goodness behind. Sometimes, better health comes down to smarter combinations already sitting in our kitchens.