This glossary defines the energy, cellular and nutrition terms used across Wellspring in plain language. Each entry gives a one-to-two-sentence definition and an “in everyday terms” note. It is general wellness education, not medical advice, and it does not recommend any product or treat any condition — see a healthcare professional for individual concerns.
- Entries are listed alphabetically — scan or use your browser’s find.
- Each term has a clean definition plus a simpler everyday reading.
- Where a nutrient has an established role, we use cautious structure–function wording (“contributes to”, “is needed for”) tied to recognised bodies such as the NIH Office of Dietary Supplements and the European Food Safety Authority.
- For the bigger picture, start with Why am I always tired?
Use this page the way you’d use a friendly footnote: when a term shows up in an article and you want it pinned down without the jargon. Definitions describe how the body normally works and what specific nutrients are known to contribute to or support — never a cure, and never a brand.
The terms, A to Z
Adenosine
Adenosine is a molecule that gradually builds up in the brain during waking hours and binds to receptors that promote sleepiness; this rising “sleep pressure” helps drive the urge to sleep at night, as described by the US National Institute of Neurological Disorders and Stroke.
In everyday terms: it’s your brain’s “how-long-have-I-been-awake” meter. Caffeine works largely by blocking adenosine’s signal, which is why it postpones — but doesn’t erase — tiredness.
Antioxidant
An antioxidant is a molecule that can neutralise reactive free radicals before they damage cells, helping keep oxidative stress in check; the body makes some antioxidants and obtains others (such as vitamins C and E) from food, per the US National Center for Complementary and Integrative Health.
In everyday terms: think of antioxidants as the clean-up crew that mops up sparks before they scorch anything. A varied, plant-rich diet usually supplies them better than any single high-dose pill.
ATP (adenosine triphosphate)
ATP is the main energy-carrying molecule inside cells: it stores chemical energy and releases it to power nearly every cellular process, from muscle contraction to nerve signalling. The US National Human Genome Research Institute describes it as the cell’s primary energy currency.
In everyday terms: ATP is the rechargeable battery your cells spend and refill constantly. “Feeling energetic” is, at the cellular level, having enough ATP made on demand.
Bioavailability
Bioavailability is the proportion of a nutrient (or compound) that is actually absorbed and made available for the body to use, rather than passing through unused. It varies by the food form, what it’s eaten with, and individual factors, as discussed by the NIH Office of Dietary Supplements.
In everyday terms: it’s the difference between what’s on the label and what your body keeps. A nutrient is only useful to the extent it’s absorbed — not the amount you swallow.
Circadian rhythm
Circadian rhythm is the roughly 24-hour internal clock that governs cycles of sleep, wakefulness, hormone release and body temperature, kept in sync mainly by light exposure, as explained by the US National Institute of General Medical Sciences.
In everyday terms: it’s your body’s daily timetable. Bright morning light and consistent sleep times keep it on schedule; late screens and erratic hours blur it, which can leave you tired at the wrong moments.
Collagen peptides
Collagen peptides are short chains of amino acids made by breaking down collagen protein, marketed for skin and joints; evidence is mixed and still developing, and any benefit relates to general structural support of the skin’s protein matrix rather than a guaranteed cosmetic outcome. See our fuller look at the evidence on collagen.
In everyday terms: a digestible form of the protein that forms much of skin and connective tissue. The science is genuinely unsettled — some studies are encouraging, others modest — so we describe it honestly rather than overselling it.
CoQ10 (coenzyme Q10)
CoQ10 is a fat-soluble compound made by the body and found in cells’ mitochondria, where it plays a role in the chain of reactions that produces ATP; it also acts as an antioxidant, and tissue levels tend to decline with age, per the US National Center for Complementary and Integrative Health.
In everyday terms: a spark plug your mitochondria use to make energy. You make your own, so a deficiency in healthy people is uncommon — read more in cellular energy & ageing.
Cortisol
Cortisol is a hormone released by the adrenal glands that helps regulate metabolism, blood sugar and the body’s response to stress; it normally follows a daily curve — higher in the morning, lower at night — as described by the Society for Endocrinology.
In everyday terms: your built-in “get-up-and-go” and stress hormone. It’s meant to rhythm with your day; the popular idea that everyday stress “wrecks” cortisol is mostly overstated — see stress, cortisol & sleep.
Ferritin
Ferritin is a protein that stores iron inside cells, and a blood ferritin test is the most common way to estimate the body’s iron stores; a low ferritin level is an early sign that iron reserves are running down, per the NIH Office of Dietary Supplements.
In everyday terms: ferritin is your body’s iron savings account. You can have “normal” haemoglobin yet a near-empty ferritin store — which is why fatigue sometimes shows up before standard “bloods” look abnormal.
Free radicals
Free radicals are unstable molecules with an unpaired electron that are produced normally during metabolism and by factors like pollution or UV light; in excess they can react with and damage cell components, as outlined by the US National Center for Complementary and Integrative Health.
In everyday terms: the sparks thrown off when cells burn fuel. A few are normal and even useful for signalling; the problem is when production outpaces your antioxidant defences — that imbalance is oxidative stress.
Glycaemic response
Glycaemic response is the rise and fall in blood glucose after eating, shaped by the type and amount of carbohydrate and what it’s combined with; a sharp spike-then-dip pattern is linked with the post-meal slump many people feel, as covered by the Harvard T.H. Chan School of Public Health.
In everyday terms: how steeply your blood sugar climbs and crashes after a meal. Pairing carbs with protein, fat and fibre flattens the curve — the practical heart of steady energy & metabolic balance.
Gut microbiome
The gut microbiome is the community of trillions of bacteria and other microbes living mainly in the large intestine, which help digest fibre, produce certain vitamins and short-chain fatty acids, and interact with the immune system, as described by the US National Institute of Diabetes and Digestive and Kidney Diseases.
In everyday terms: the busy ecosystem of microbes in your gut. A diverse, fibre-fed community is generally associated with better digestion and wellbeing — fed mostly by plants, not by any single supplement.
Magnesium glycinate
Magnesium glycinate is a form of the mineral magnesium bound to the amino acid glycine, often chosen because it tends to be well tolerated by the digestive system; magnesium itself contributes to normal energy-yielding metabolism and normal muscle and nervous-system function, per European Food Safety Authority assessments.
In everyday terms: a gentle-on-the-stomach version of magnesium. Magnesium matters for energy and muscle and nerve function; the “glycinate” part is mainly about comfort and absorption — see foundational nutrient status.
Mitochondria
Mitochondria are tiny structures inside almost every cell that convert nutrients and oxygen into usable energy (ATP); often called the cell’s “powerhouses,” their number and efficiency influence how much energy a tissue can produce, as described by the US National Human Genome Research Institute.
In everyday terms: the little power stations in your cells. When people talk about “cellular energy,” this is mostly what they mean — explained plainly in cellular energy & ageing.
Omega-3 (EPA & DHA)
Omega-3 fatty acids are a family of fats the body can’t fully make on its own; the long-chain forms EPA and DHA come mainly from oily fish, and DHA in particular contributes to the maintenance of normal brain function and vision, per European Food Safety Authority assessments.
In everyday terms: “good fats” found mostly in oily fish like salmon and sardines. EPA and DHA are the two that get the most research attention for heart and brain wellbeing.
Oxidative stress
Oxidative stress is the imbalance that occurs when free radicals outnumber the antioxidants available to neutralise them, allowing damage to cells, proteins and DNA to accumulate over time; it is widely studied in the context of ageing, as summarised by the US National Center for Complementary and Integrative Health.
In everyday terms: when the “sparks” outpace the “clean-up crew.” It’s a normal process pushed out of balance — which is why lifestyle (sleep, diet, not smoking) matters more than chasing antioxidant megadoses.
Postbiotics
Postbiotics are the beneficial compounds produced when gut bacteria ferment fibre — such as short-chain fatty acids — or preparations of inactivated microbes and their components; they are an emerging area of microbiome research, with definitions still being refined by bodies such as the International Scientific Association for Probiotics and Prebiotics.
In everyday terms: the helpful by-products your gut microbes make after a fibre-rich meal. The science is young, so we treat strong product claims with caution.
RNI / RDA (recommended intake)
RNI (Recommended Nutrient Intake, the term used in Malaysia’s national guidelines) and RDA (Recommended Dietary Allowance) are the average daily nutrient amounts judged sufficient to meet the needs of most healthy people in a group; Malaysia’s values are set out in the Ministry of Health Malaysia RNI 2017.
In everyday terms: the “how much per day” targets nutrition guidelines use. They’re population averages, not a personal prescription — individual needs can differ.
Structure-function claim
A structure–function claim is a permitted statement describing how a nutrient supports the body’s normal structure or function (for example, “iron contributes to the reduction of tiredness and fatigue”) without claiming to diagnose, treat, cure or prevent disease; this wording is governed in Malaysia by NPRA and food-labelling regulations.
In everyday terms: the careful, legally allowed way to talk about what a nutrient does. It’s why we say a nutrient “contributes to” or “is needed for” something — never that it cures anything. See how we apply this in our disclosures.
Vitamin B12 (cobalamin)
Vitamin B12 is a water-soluble vitamin found naturally in animal foods that contributes to normal red-blood-cell formation, normal energy-yielding metabolism and normal nervous-system function; deficiency is more common in older adults and those on plant-only diets, per the NIH Office of Dietary Supplements.
In everyday terms: a vitamin your body needs for healthy blood and nerves — and a real, checkable cause of fatigue. It’s mainly in meat, fish, eggs and dairy, so strict vegetarians watch it most.
Vitamin D
Vitamin D is a fat-soluble vitamin the skin can make from sunlight and that is found in a few foods; it contributes to normal muscle function and the normal absorption and use of calcium, and many people in indoor, sun-avoidant lifestyles have low levels, per the NIH Office of Dietary Supplements.
In everyday terms: the “sunshine vitamin.” Even in sunny Malaysia, office life, sun avoidance and covering up mean low levels are surprisingly common — a worthwhile thing to check. More in foundational nutrient status.
Frequently asked questions
Is this glossary medical advice?
No. These definitions are general wellness education to help you understand the words used across Wellspring. They describe how the body normally works and what nutrients are known to support — they do not diagnose, treat or recommend anything. For any individual concern, please speak with a qualified healthcare professional.
Why do you say a nutrient “contributes to” energy instead of “boosts” it?
Because that cautious wording — a structure-function claim — is both more accurate and what Malaysian rules (NPRA and food-labelling regulations) allow. A nutrient can be genuinely needed for a normal process without it being a stimulant or a cure. We keep that distinction throughout the site.
Do I need to know all these terms to understand the site?
Not at all. Articles are written to be clear on their own, and we link to this glossary the first time a term appears. Treat it as an optional footnote you can dip into whenever a word makes you pause.
Where should I start if I just feel tired all the time?
Begin with our pillar guide, Why am I always tired? It walks through the most common, checkable drivers of everyday fatigue — and the terms here will already feel familiar by the end.
References
- ATP definition (US National Human Genome Research Institute) — supports the ATP and mitochondria entries.
- Iron fact sheet (NIH Office of Dietary Supplements) — supports the ferritin and bioavailability entries.
- Antioxidants in depth (US NCCIH) — supports the antioxidant, free radicals and oxidative stress entries.
- Coenzyme Q10 (US NCCIH) — supports the CoQ10 entry.
- Circadian rhythms (US NIGMS) — supports the circadian rhythm and adenosine entries.
- Vitamin B12 fact sheet (NIH ODS) — supports the vitamin B12 entry.
- Vitamin D fact sheet (NIH ODS) — supports the vitamin D entry.
- Magnesium claims assessment (EFSA) — supports the magnesium glycinate entry.
- DHA/EPA claims assessment (EFSA) — supports the omega-3 entry.
- Recommended Nutrient Intakes for Malaysia 2017 (Ministry of Health Malaysia) — supports the RNI/RDA entry.
- Carbohydrates and blood sugar (Harvard T.H. Chan School of Public Health) — supports the glycaemic response entry.
- The digestive system (US NIDDK) — supports the gut microbiome entry.