Vitamins appear on almost every food and supplement label. They come with health claims, reference intake percentages, and an ever-growing range of marketing language. But what a vitamin actually is, how it functions in the body, and why the source matters are questions that food packaging rarely bothers to answer.
This guide covers the science clearly - from what vitamins are and how they work, to why fortification exists, what the food matrix effect means in practice, and why the distinction between natural and synthetic sources is more significant than most product labels currently acknowledge.
What Are Vitamins?
Vitamins are organic compounds required by the body in small amounts to support normal physiological function. They are part of a group called micronutrients - alongside minerals like iron, zinc, calcium, and magnesium - which are needed in much smaller quantities than macronutrients but are absolutely essential for health.
The distinction between macro and micronutrients is important. Macronutrients - carbohydrates, fats, and proteins - provide energy and structural building blocks. Micronutrients do not provide energy in themselves. Instead, they enable the metabolic processes that allow the body to use energy and to build and repair tissues. Without adequate micronutrient intake, those processes break down - sometimes with consequences that are slow to develop and easy to miss until they become serious.
“Micronutrients are needed in much smaller amounts than macronutrients, but they are still absolutely essential for health. The challenge is that deficiency is often silent. People can be within a healthy weight range and still be significantly deficient in Vitamin D, iron, iodine, or folate - nutrients that are critical for everything from immune function to neurological development. That invisibility is part of why good fortification matters so much.” - Eimear Sutton, RNutr MSc - Head of Nutrition, BIOVIT
Water-Soluble and Fat-Soluble: Why the Distinction Matters
Vitamins are classified into two groups based on how they are absorbed and stored in the body.
Water-soluble vitamins - the B vitamins (B6, B12, Biotin, Folate, and others) and Vitamin C - dissolve in water and circulate freely in the body. Because they are not extensively stored in tissue, they need to be consumed regularly. Excess amounts are generally excreted in urine rather than accumulated, which also means deficiency can develop more quickly if intake drops.
Fat-soluble vitamins - A, D, E, and K - are absorbed in the presence of dietary fat and can be stored in body tissues, particularly the liver and fatty tissue. This means they can accumulate over time, and very high supplemental doses of some fat-soluble vitamins carry toxicity risks. It also means that people on very low-fat diets, or with conditions affecting fat absorption, may be at particular risk of deficiency.
For food brands and formulators, this distinction has practical implications. Fat-soluble vitamins need to be incorporated into formats that contain or are consumed alongside fat. Water-soluble vitamins in liquid formats need to be protected from light and oxidation, which can degrade them before the product reaches the consumer.
Major Vitamins and Minerals: Roles and Natural Sources
The table below covers the major vitamins and minerals, their key roles in the body, and the natural food source from which BIOVIT derives each one. The fourth column is relevant to any brand considering the switch from synthetic to natural fortification - it shows that every nutrient has a traceable, food-based origin.
Vitamin
Type
Key Roles in the Body
BIOVIT Natural Source
Vitamin A
Fat-soluble
Normal vision, immune function, skin and mucous membrane maintenance
Moringa leaf
Vitamin C
Water-soluble
Collagen synthesis, immune function, iron absorption, protection from oxidative stress
Acerola cherry or Amla
Vitamin D2
Fat-soluble
Calcium absorption, bone maintenance, immune function, muscle function
Shiitake mushroom
Vitamin D3
Fat-soluble
Calcium absorption, bone and muscle health, immune function, cell division
Lichen
Vitamin E
Fat-soluble
Protection of cells from oxidative stress
Moringa leaf
Vitamin B6
Water-soluble
Protein and glycogen metabolism, red blood cell formation, nervous system, immune function
Lemon peel
Vitamin B12
Water-soluble
Red blood cell formation, neurological function, DNA synthesis, energy metabolism
Shiitake mushroom
Biotin (B7)
Water-soluble
Normal macronutrient metabolism, nervous system function, psychological function, hair and skin
Sunflower seeds
Folate (B9)
Water-soluble
Cell division, blood formation, amino acid synthesis, maternal tissue growth in pregnancy
Spinach leaf
Calcium
Mineral
Bone and teeth maintenance, muscle function, nerve transmission, blood clotting
Marine algae
Iron
Mineral
Red blood cell production, oxygen transport, energy metabolism, cognitive function
Curry leaf
Zinc
Mineral
Immune function, DNA synthesis, fertility, skin, hair, nails, protein synthesis
Guava leaf
Magnesium
Mineral
Muscle function, nervous system, energy metabolism, bone maintenance, protein synthesis
Sea water
Selenium
Mineral
Antioxidant protection, thyroid function, immune function, hair and nail maintenance
Sunflower seeds
Iodine
Mineral
Thyroid hormone production, cognitive function, energy metabolism, skin maintenance
Seaweed
Chromium
Mineral
Normal macronutrient metabolism, blood glucose regulation
Parsley
The Food Matrix: Why Source Is More Than a Marketing Point
When vitamins are present in whole foods, they do not exist in isolation. They are embedded in a complex structure of proteins, fats, carbohydrates, fibre, and other bioactive compounds - a structure known as the food matrix. This matrix can influence how nutrients are released during digestion, how effectively they are absorbed, and what happens to them once they enter circulation.
Vitamin C from an acerola cherry does not arrive in the body as a single isolated molecule. It arrives alongside flavonoids, polyphenols, and other plant compounds that can enhance its absorption and extend its antioxidant activity in the body. The same is true of iron in curry leaf - it is accompanied by organic acids and compounds that modulate its absorption in ways that isolated ferrous sulphate cannot replicate.
The most directly relevant evidence for food matrix effects comes from studies comparing whole food sources of nutrients against isolated supplements delivering equivalent doses. Research consistently shows that vitamin C from food sources is associated with greater antioxidant capacity in the blood than equivalent doses from isolated ascorbic acid - even when circulating plasma concentrations are similar. This suggests that the co-factors travelling alongside the vitamin are doing meaningful work that the isolated compound alone does not accomplish.
“The food matrix effect is real and it is underappreciated. The way we tend to measure nutrient absorption - by looking at what appears in the bloodstream - gives us only part of the picture. The co-factors present in a food-derived ingredient can influence inflammation, oxidative stress, and cellular uptake in ways that blood level measurements alone do not capture. This is one of the reasons that food-derived nutrients are increasingly valued in both consumer products and clinical nutrition.” - Eimear Sutton, RNutr MSc - Head of Nutrition, BIOVIT
It is important to be clear about what the food matrix evidence does and does not show. It does not demonstrate that food-derived vitamins are more bioavailable in the sense of reaching higher blood concentrations - the Swansea University clinical trial conducted for BIOVIT found equivalent bioavailability between organic and synthetic sources across eight blood markers over 30 days. What it suggests is that food-derived vitamins may deliver additional biological activity beyond the nutrient itself, through the co-factor compounds present in the food matrix.
Why Vitamins Are Added to Food - and Where It Started
Many people consume adequate calories while being deficient in micronutrients. This is particularly common with Vitamin D (where dietary sources are limited and sun exposure in the UK is insufficient for much of the year), iron (especially in women of reproductive age and people avoiding red meat), iodine (increasingly deficient as dairy consumption falls), and folate (critical during early pregnancy).
Food fortification - the deliberate addition of vitamins and minerals to a food product - was developed as a public health response to exactly this problem. It first emerged in the United States in the 1920s, when iodine was added to salt to address widespread goitre, and Vitamin D was added to milk to combat the epidemic of rickets that had developed in industrialised cities where children had limited sun exposure.
In the UK today, fortification of white and brown flour is mandatory. Calcium, iron, Vitamin B1, and Vitamin B3 must be present at specified levels. Folic acid has more recently been added to this list following decades of evidence and campaigning around its role in preventing neural tube defects in early pregnancy.
Why food brands add vitamins today
- To achieve the 15% reference intake threshold required to make an authorised health claim on pack
- To replace nutrients lost during heat processing (UHT, baking, retort)
- To match the nutritional profile of the animal-based product being replaced (plant-based milks, meat alternatives)
- To meet the specific needs of target consumer groups - vegans, athletes, older adults, children
- To position a product meaningfully within the functional food category
Natural vs Synthetic Vitamins: The Source Question
Most vitamins added to food and supplements today are synthetic - manufactured either through chemical synthesis from petrochemical precursors, or through microbial fermentation. The resulting compounds are chemically identical to the vitamin molecule found in food, but they lack the food matrix - the co-factors, phytonutrients, and structural context - that accompanies that nutrient in its natural state.
Natural vitamins are derived from food sources - plants, algae, fungi - and retain that food matrix context. When they appear on a product label, they appear as the food they came from: acerola cherry, shiitake mushroom, curry leaf, lichen. When synthetic vitamins appear on a label, they appear by chemical name: ascorbic acid, cyanocobalamin, cholecalciferol, ferrous sulphate.
For consumers, this distinction is already commercially significant. Research by BIOVIT in partnership with Vypr found that 92% of UK consumers would prefer the vitamins and minerals in their food products to be natural. A survey of 5,000 European consumers by Safe Food Advocacy Europe found that 83% consider it important to know whether vitamins in a product are natural or synthetic.
For brands, the question is how to close the gap between what consumers expect and what the label currently has to say. Natural fortification is the answer that makes that gap disappear - because the label reads like food.
“The most important shift happening in food fortification right now is the move from asking whether vitamins work, to asking where they come from. The answer to the first question has always been yes. The second question is what consumers are now demanding - and what brands that care about their ingredient story need to be able to answer clearly.” - Eimear Sutton, RNutr MSc - Head of Nutrition, BIOVIT
Natural Vitamins for Food and Drink - From Plants, Algae, and Fungi
BIOVIT supplies a full range of organically certified vitamins and minerals derived from natural sources, with clinically proven bioavailability and processing stability data across all major food formats.
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