Bioavailability: Getting the Most of of Baby Meals
Why bioavailability matters in baby meals
Not all of what we eat is taken in and utilized by our bodies. Only a portion of the nutrients from food can be absorbed into our bodies to be used. Bioavailability is the overall measurement of how certain nutrients in food are digested, absorbed, and distributed throughout the body [1,2,3,4]. For example, studies have shown that as little as 2% of iron from spinach is actually absorbed by the body compared to the 15 -35% of iron from meat that is absorbed .
Bioavailability matters for baby meals due to avoid potential nutritional deficiencies [1,4]. Babies grow fast and need a lot of nutrition and energy. However, even well-fed babies can be exposed to a risk of nutritional deficiency depending on how meals are designed.
What increases or decreases bioavailability
A lot of factors affect the level of bioavailability throughout the gastrointestinal tract. For example, proteins generally form soluble complexes with zinc, iron, and copper to increase the absorption of these minerals . The products of fat digestion can increase absorption of fat-soluble A,B,E and K vitamins .
On the other hand, oxalate, phytate, polyphenols, and dietary fibers (found in a variety of cereals, legumes, nuts, and green vegetables) disrupt enzyme interactions and block the absorption of iron, zinc, proteins, and lipids (fats) by the body [1,3].
It’s hard to control what’s happening inside of the body, but we can certainly increase bioavailability by pairing certain foods together, or preparing food in an easy-to-absorb form.
Increase bioavailability with spices and acids
Spices are common flavor and taste enhancers added to food, but they are also are absorption enhancers in the intestine.
- Spice molecules, such as capsaicin (red pepper), piperine (black pepper), gingerol and gingerone (ginger), alter the lining of the intestines to open up their permeability . This increases the absorption of iron, zinc, calcium, and B-carotene (Vitamin A precursor) by significant percentages (10-150%) .
- Garlic and onions both increase the absorption of iron and zinc when they are cooked with grains 
- Acids in citrus foods and fermented milk products increase b-carotene, zinc, and iron absorption through the formation of soluble complexes in the gut [1,3]. The addition of lime juice to grains can have a significant impact on a meal's nutritional value in terms of iron and zinc [1,3].
Increase bioavailability by cooking
Cooking in general can help your baby absorb more nutrients for his/her growth.
- Heat processing, such as microwave and pressure cooking, generally increases a food’s digestibility by loosening up the food matrix, and freeing up certain nutrients for absorption. Heating also reduces chemicals like phytate, which lower nutrient absorption [1,2].
- Mechanical Processing, like cutting, blending, and milling can work in a similar fashion to heat processing. Certain nutrients are released from the food structure and more easily processed, while others are destroyed before ingestion [1,2].
- Soaking works similarly, as water soluble nutrients and phytates are leached out, leaving iron and zinc more available for absorption [1,2]. For example, pre-soaking chickpeas and lentils overnight before cooking increases their bioavailability.
- Platel K, Srinivasan K. "Bioavailability of Micronutrients from Plant Foods: An Update." Critical Reviews in Food Science and Nutrition 56, no. 10 (2015): 1608-619. doi:10.1080/10408398.2013.781011.
- Hotz C, Gibson RS. "Traditional food-processing and preparation practices to enhance the bioavailability of micronutrients in plant-based diets." The Journal of nutrition 137, no. 4 (2007): 1097-1100.
- Gibson RS, Perlas L, Hotz C. "Improving the bioavailability of nutrients in plant foods at the household level." Proceedings of the Nutrition Society 65, no. 02 (2006): 160-68. doi:10.1079/pns2006489.