What Are Biomolecules?

For the duration of the past century, since the great Polish scientist Casimir Funk created his list of Vital-Amines¹ and coined the term in 1912, there has been tremendous controversy about what actually constitutes a “vitamin.” The definition of the very word vitamin has gradually become synonymous with a pill or capsule containing nutritional components, but this is not an accurate scientific definition.

There are many nutrients commonly referred to as vitamins that do not necessarily meet the modern definition of a vitamin, while still remaining absolutely vital to human biochemistry. This article proposes a broader and more accurate classification system by referring to these compounds collectively as Biomolecules.

These Vital Chemicals, or biomolecules², can be divided into three distinct categories:

• Essential Biomolecules
• Conditionally Essential Biomolecules
• Non-essential Biomolecules

Essential Biomolecules

Essential Biomolecules are nutrients that are indispensable to human biology but cannot be synthesized directly by the body. They must therefore be obtained through food or supplementation.

Examples include many of the B-complex vitamins, such as:

• Vitamin B1 (Thiamine)
• Vitamin B2 (Riboflavin)
• Vitamin B5 (Pantothenic Acid)
• Vitamin B6 (Pyridoxine)
• Vitamin A
• Vitamin E

Niacin (Vitamin B3), however, does not fit neatly into this category because the body can manufacture some niacin from the essential amino acid tryptophan. Since this conversion occurs but is generally inefficient and often insufficient to satisfy biological demand, niacin is better classified as a Conditionally Essential Biomolecule.

Vitamin C presents another interesting example. Approximately 99.99% of mammals manufacture their own vitamin C, whereas humans cannot. Consequently, vitamin C is essential for humans despite being non-essential for nearly every other mammal.

Minerals as Essential Biomolecules

Minerals can also be regarded as Essential Biomolecules because they serve as the chemical building blocks of life and cannot be synthesized by the body.

Examples include:

• Magnesium
• Calcium
• Potassium
• Sodium
• Zinc
• Copper
• Manganese

Macronutrients—including proteins, carbohydrates and fats—also belong in this category because they must be obtained from food and cannot be produced by the body in sufficient quantities.

Conditionally Essential Biomolecules

Conditionally Essential Biomolecules occupy the middle ground. These substances can be synthesized by the body, but not efficiently enough—or not in adequate amounts—to meet physiological demand.

Niacin is a classic example.

Omega-3 fatty acids also fit this classification. Although often labeled “essential,” the long-chain omega-3 fatty acids EPA and DHA are actually synthesized from dietary Alpha-Linolenic Acid (ALA). Unfortunately, this conversion occurs very slowly and rarely produces sufficient quantities for optimal health.

Therefore, while omega-3 fatty acids are unquestionably vital for normal physiology, they are more accurately described as Conditionally Essential Biomolecules rather than strictly essential nutrients.

Other Examples

Other compounds that may fall into this category include:

• Coenzyme Q10 (CoQ10)
• Alpha Lipoic Acid
• Glutathione

The body manufactures these compounds, but often not in amounts sufficient to satisfy biological requirements.

The Importance of Conversion Cofactors

Conditionally Essential Biomolecules often depend upon other nutrients known as conversion cofactors.

For example, niacin synthesis from tryptophan requires adequate levels of:

• Vitamin C
• Vitamin B6

If this conversion pathway fails or produces insufficient niacin, the deficiency disease pellagra may develop³. Even when enough niacin is produced to prevent pellagra, production may still fall short of supporting optimal health.

Carnitine: Another Example

Carnitine is generally regarded as a Conditionally Essential Amino Acid because the body synthesizes it inefficiently using two hydroxylase enzymes.

Carnitine is essential for transporting fatty acids into mitochondria, where they are converted into energy.

Vitamin C plays a crucial role in this process by supporting the hydroxylase enzymes involved in carnitine production. Iron must also remain in the correct oxidation state at the enzyme’s active site, and vitamin C helps stabilize iron so this reaction can occur efficiently.

This illustrates how one conditionally essential biomolecule may depend entirely upon several essential biomolecules for both its synthesis and function.

As a result, determining whether a nutrient is essential, conditionally essential or non-essential often requires individual assessment using:

• Laboratory testing
• Dietary analysis
• Scientific literature
• Clinical history
• Professional consultation

Human nutrition is rarely as straightforward as broad classifications might suggest.

Non-essential Biomolecules

Non-essential Biomolecules are substances that remain vital to human health but are normally synthesized by the body from other nutrients or precursor molecules.

Examples include:

• Non-essential amino acids
• Hormones
• Vitamin D

Why Vitamin D Is Technically Non-essential

Although this classification may seem surprising, vitamin D is technically produced by the body from cholesterol in the presence of sunlight and several nutritional cofactors, including:

• Vitamin C
• Magnesium
• Adequate sunlight exposure

Supplementing with large doses of vitamin D3 does not necessarily ensure the production of biologically active vitamin D if these conversion cofactors are lacking.

In cases of severe deficiency, vitamin D may temporarily function as a Conditionarily Essential Biomolecule. However, these deficiencies frequently arise because the nutrients required for vitamin D metabolism—particularly vitamin C and magnesium—are themselves deficient.

Changing Circumstances

Even Non-essential Biomolecules may become deficient if synthesis pathways are impaired due to:

• Trauma
• Disease
• Organ dysfunction
• Surgical procedures
• Menopause

For example, hormone production following hysterectomy or menopause may become inadequate, making bioidentical hormone replacement therapy (BHRT) necessary to restore biochemical balance.

Under these circumstances, hormones effectively become essential because the body can no longer produce sufficient quantities on its own.

Understanding the Terminology

It is important not to confuse the terms essential and non-essential with judgments about importance.

Within this proposed classification:

• Essential means the nutrient must be obtained externally through diet or supplementation because the body cannot manufacture it.
• Non-essential means the body normally possesses the ability to synthesize or convert the compound.
• Conditionally Essential describes substances that the body can manufacture but not efficiently enough to consistently meet physiological requirements.

A New Perspective on Biomolecules

The broader classification of Biomolecules may better reflect our modern understanding of nutritional science than relying solely on the traditional concept of vitamins.

Terms such as “Vitamin” D⁴, “Vitamin” B3⁴, and “Vitamin” B12⁴ may no longer fully communicate the biological complexity and physiological roles of these compounds.

Developing more precise definitions and classifications could improve communication among scientists, healthcare practitioners and nutritional product developers while leading to more effective clinical applications.

By expanding upon Casimir Funk’s original concept of Vital-Amines, we may continue advancing our understanding of the biochemical compounds that are fundamental to long-term health, optimal function and effective healing.

References

1. Casimir Funk’s original work describing the concept of Vital-Amines (1912).
2. Proposed classification of biomolecules as described in this article.
3. Pellagra resulting from niacin deficiency.
4. Conventional vitamin nomenclature.