What Changes After You Take a Bite?
We hear plenty about what to eat. Less about what happens after we take that first bite.
Food goes through a series of processes before the body can use the nutrients it contains. Digestion breaks food down, nutrients are released, and the digestive system absorbs them so they can be transported around the body.
But does this process stay exactly the same throughout our lives?
Not necessarily.
Ageing can bring gradual changes to the digestive system and other parts of the body. Stomach acid production may change, certain nutrients may become more difficult to absorb, and the way the body produces or retains some nutrients can also be affected.
However, these changes are not the same for everyone. Healthy older adults generally continue to digest and absorb most major nutrients, including protein, fats and carbohydrates.
The interesting part is that some nutrients deserve a closer look.
From vitamin B12 and calcium to magnesium and vitamin D, here are seven facts worth knowing about ageing, digestion and nutrient absorption.
7 Facts Worth a Closer Look
1. Your Gut Doesn't Simply Stop Working Well
One common misconception about ageing is that the digestive system gradually loses its ability to absorb everything we eat.
That is not quite how it works.
Research indicates that healthy older adults generally continue to absorb most macronutrients effectively. These include:
- Protein: Broken down into amino acids during digestion.
- Carbohydrates: Broken down into simpler sugars.
- Fats: Digested into smaller components that can be absorbed through the digestive tract.
The digestive system continues to perform these important functions as we get older.
However, some changes can occur in the digestive system. Stomach acid production, digestive function, appetite and the movement of food through the digestive tract may vary with age and individual health circumstances.
Underlying conditions and certain medications can also influence digestion and nutrient availability.
This is why it is misleading to assume that everyone experiences poor nutrient absorption simply because they are getting older.
What to remember: Ageing does not automatically mean your digestive system stops working properly. A varied diet remains an important part of everyday nutrition throughout adulthood.
2. Vitamin B12 Can Become Trickier to Absorb
Vitamin B12 is one nutrient that deserves attention as we get older.
It is naturally found in animal-based foods, including:
- Beef and other meats
- Fish and seafood
- Eggs
- Milk and dairy products
But eating foods containing vitamin B12 is only one part of the process. The body also needs to release the vitamin from the food before it can be absorbed.
This is where stomach acid comes in.
Why does stomach acid matter?
In animal-based foods, vitamin B12 is attached to proteins. During digestion, stomach acid helps release the vitamin from those proteins.
Some older adults produce less stomach acid. This can make it harder to release vitamin B12 from food, potentially affecting how much becomes available for absorption.
There is another important part of the process: intrinsic factor.
Intrinsic factor is a protein produced in the stomach. It helps vitamin B12 travel through the digestive system so it can be absorbed in the small intestine.
Changes affecting either stage can influence vitamin B12 absorption.
Where can vitamin B12 be found?
Food sources include:
- Meat
- Fish and shellfish
- Eggs
- Milk and dairy products
- Foods fortified with vitamin B12
People who follow vegetarian or vegan eating patterns may need to pay particular attention to reliable sources of vitamin B12, such as appropriately fortified foods.
What to remember: Vitamin B12 absorption involves more than simply eating foods that contain the vitamin. If you have concerns about your intake or absorption, speak with a healthcare professional about your individual needs.
3. Calcium Absorption Can Decline
Calcium is commonly associated with bones and teeth, but its role in the body goes beyond that.
It is also involved in normal muscle contraction, nerve signalling and other important body processes.
As we age, the amount of calcium absorbed from the digestive tract can change.
Hormonal changes, particularly the reduction in oestrogen after menopause, are also relevant to bone health.
Why does menopause matter?
Oestrogen plays a role in regulating the natural process of bone renewal.
After menopause, lower oestrogen levels can increase the rate at which bone is broken down. This can contribute to changes in bone density over time.
That is one reason calcium intake and overall dietary variety remain important considerations as women get older.
Where can calcium be found?
Everyday food sources include:
- Milk, yoghurt and cheese
- Calcium-fortified plant-based drinks
- Calcium-set tofu
- Sardines and salmon with edible bones
- Some green vegetables, including kale and bok choy
Vitamin D is also involved in calcium absorption, so the two nutrients are often discussed together.
What to remember: Calcium intake is one part of overall bone health. Age, hormonal changes, dietary patterns and individual health circumstances can all influence nutritional needs.
4. Magnesium Absorption and Retention May Change Too
Magnesium is found in a variety of everyday foods, yet it is not always the first nutrient people think about when discussing nutrition and ageing.
It is involved in many processes in the body, including energy metabolism, protein synthesis and normal muscle and nerve function.
Research suggests that some older adults may absorb less magnesium through the digestive tract. The kidneys may also excrete more magnesium in some circumstances.
This means that changes in both absorption and retention can be relevant.
Where can you find magnesium?
Magnesium-containing foods include:
- Pumpkin seeds
- Almonds and cashews
- Spinach and leafy vegetables
- Whole grains
- Beans and lentils
- Some other nuts and seeds
These foods can easily become part of everyday meals.
For example, you could add pumpkin seeds to breakfast, include beans in a lunch salad or choose whole grains as part of dinner.
Why food variety matters
Different foods contain different combinations of nutrients. Relying on a limited selection of foods may make it harder to achieve a varied nutritional intake.
Including vegetables, legumes, nuts, seeds and whole grains throughout the week is one practical way to broaden your food choices.
What to remember: Magnesium intake and retention can be influenced by age, diet, kidney function and other individual factors. If you are considering magnesium products, discuss your circumstances with a healthcare professional, particularly if you have kidney-related concerns or take regular medication.
5. Vitamin D Is a Different Story
Vitamin D is interesting because the change associated with ageing is not necessarily about absorbing it from food.
Your skin can produce vitamin D when exposed to ultraviolet B (UVB) radiation from sunlight.
However, this process becomes less efficient with age.
Older skin generally produces less vitamin D from the same amount of UVB exposure than younger skin.
This is a change in vitamin D production, rather than proof that the digestive system is absorbing less vitamin D from food.
Where does vitamin D come from?
There are two main sources to understand.
Sunlight
The skin produces vitamin D following exposure to UVB radiation. The amount produced varies with factors such as age, skin pigmentation, season, location, time outdoors and sun protection.
Food
Some foods naturally contain vitamin D, while others may have vitamin D added during manufacturing.
Examples include:
- Oily fish such as salmon and sardines
- Egg yolks
- Some fortified milk and plant-based drinks
- Certain fortified breakfast cereals
Vitamin D is fat-soluble, which means it is absorbed along with dietary fat.
What should you remember?
Ageing can influence how much vitamin D the skin produces, but individual vitamin D status is affected by several factors.
It is not advisable to rely on excessive sun exposure to increase vitamin D production. Follow appropriate sun protection guidance and seek professional advice if you have concerns about your vitamin D intake or status.
6. Medicines Can Play a Part
Age is not the only factor that can influence nutrient absorption.
Some medicines can also affect how the body processes or absorbs particular nutrients.
Vitamin B12 is one example.
Two types of medication commonly discussed in relation to vitamin B12 status are metformin and certain stomach-acid-reducing medicines.
Metformin
Metformin is a medicine commonly prescribed for blood glucose management.
Long-term use has been associated with lower vitamin B12 levels in some people.
Stomach-acid-reducing medicines
Some medicines reduce the amount of acid produced in the stomach.
Examples include proton pump inhibitors and H2-receptor antagonists.
Because stomach acid helps release vitamin B12 from food proteins, prolonged use of certain acid-reducing medicines may influence how much food-bound B12 becomes available for absorption.
What should you do?
If you take medication regularly, it can be useful to understand whether it may affect your nutritional status.
You can ask your pharmacist or healthcare professional:
- Could this medicine affect my vitamin B12 levels?
- Is monitoring recommended for my circumstances?
- Should I discuss my dietary intake or testing with my doctor?
Never stop or change prescribed medication without professional advice.
What to remember: Medication history is one part of understanding individual nutritional needs. Your pharmacist or doctor can help explain whether a particular medicine requires any monitoring.
7. The Form of a Nutrient Can Matter
Here is another interesting fact about vitamin B12: the form in which it appears in food can influence the first stage of its digestion.
Naturally occurring vitamin B12 in meat, fish, eggs and dairy is attached to food proteins.
As discussed earlier, stomach acid helps release it from those proteins before it can move through the normal absorption process.
Vitamin B12 added to fortified foods is different.
It is not attached to food proteins in the same way. This means it bypasses the initial step of releasing B12 from food proteins.
This can be relevant for people who have difficulty releasing food-bound vitamin B12 during digestion.
Which foods may contain added vitamin B12?
Depending on the product, examples include:
- Fortified breakfast cereals
- Fortified plant-based milk alternatives
- Certain fortified nutritional foods
Always check the nutrition information panel. Not every cereal or plant-based drink contains added vitamin B12.
There is one important detail: fortified vitamin B12 still requires intrinsic factor for normal absorption. It does not bypass every stage of the absorption process.
People with certain absorption difficulties may need individual assessment rather than relying on fortified foods alone.
What to remember: Nutrients can be present in different forms in different foods. Understanding those differences can help you make more informed food choices.
What Can You Do With This Information?
Learning about nutrient absorption does not mean you need to completely change your eating habits as soon as you reach a certain age.
It simply gives you more information to consider when planning meals and discussing your nutritional needs.
Here are some practical starting points.
Eat a Variety of Protein Foods
Include different protein-containing foods throughout the week, such as fish, eggs, meat, dairy products, tofu, beans and lentils.
Include Different Sources of Calcium
Milk, yoghurt, cheese, calcium-fortified alternatives and calcium-set tofu can all contribute to dietary variety.
Add Nuts, Seeds and Whole Grains
These foods can contribute magnesium and other nutrients to everyday meals.
Include Foods Containing Vitamin B12
Meat, fish, eggs and dairy products are examples of naturally occurring vitamin B12 sources. Fortified foods may also be suitable options, depending on your dietary pattern.
Choose a Variety of Vegetables
Different vegetables provide different combinations of nutrients. Try including a range of colours and types throughout the week.
Review Your Medication Questions
If you take medicines regularly, ask your healthcare professional whether any nutrient monitoring is relevant to you.
Pay Attention to Changes in Your Eating Habits
Appetite, food preferences, digestion and meal routines can change over time. If you notice persistent changes or have concerns about your nutritional intake, discuss them with a healthcare professional.
Exploring Food Ingredients: Nutra Nourished Organic Beef Liver Capsules
Beef liver is a traditional food ingredient used in different food cultures. It is also available in different formats, including fresh, frozen and capsule products.
For people interested in this ingredient but who prefer a capsule format, Nutra Nourished offers Organic Beef Liver Capsules.
The product is made using freeze-dried beef liver and is presented in capsule form. If you are interested in exploring the product, you can review its current ingredient, sourcing and serving information on the product page.
This is a product-format option, not a recommendation for managing vitamin B12 absorption or correcting a nutrient deficiency. Individual dietary requirements vary, and anyone concerned about their vitamin B12 levels should seek appropriate professional advice.
A Little Knowledge. A Useful Next Step.
Ageing does not mean your digestive system suddenly stops working.
Many healthy older adults continue to absorb most major nutrients effectively. However, certain nutrients may be affected by changes in stomach acid, hormones, kidney function, medication use and other individual circumstances.
Vitamin B12, calcium and magnesium are worth understanding, while vitamin D production in the skin can also change with age.
The most useful takeaway is to avoid making assumptions about what your body needs.
A varied diet, an understanding of your medication history and conversations with qualified healthcare professionals can help you make more informed decisions about nutrition at every stage of life.
At your next GP or dietitian appointment, consider asking:
"Could my diet or medicines affect how I absorb nutrients?"
Your nutritional needs deserve an individual answer.
Need some help?
Do you have any questions about our supplements or looking for a guide to help you purchase the best supplement? We're happy to help!
Simply send us a message!