Why are there no B vitamins in the products?

Vitamin B group — these are water-soluble compounds involved in essential metabolic processes, including energy metabolism, nervous system function, and blood formation.

The most sensitive to environmental factors in this group are:

• Vitamin B2 (riboflavin) — especially photosensitive.
• Folic acid (B9) — degrades under the influence of light and oxygen.
• Vitamin B12 (cobalamin) — sensitive to light, especially in solution.

Bright light, especially with a high proportion of ultraviolet, causes photodestruction of vitamins:

• Riboflavin (B2) breaks down within 1–2 hours of exposure to light. The degradation rate can reach up to 50% per hour, especially if the product is in transparent packaging (e.g., milk in a glass bottle).
• Folic acid (B9) begins to degrade under direct sunlight or artificial light (especially fluorescent), particularly in an aqueous environment or when heated.
• B12 quickly degrades under the influence of light and temperature, especially if the product is crushed or opened.

Example — milk

Milk left in a glass bottle in the light:

• loses up to 80% of vitamin B2 in 2–3 hours.
• also loses B12, but to a lesser extent, as it is contained in protein structures and is not fully available for photolysis.

In industrial conditions, milk and dairy product manufacturers are switching to opaque packaging specifically to preserve vitamin B2.

Example — greens and vegetables

Greens (spinach, parsley) stored under bright light (e.g., on a supermarket shelf or in the sun):

• lose B9 (folate) within a few hours;
• folic acid can degrade by 30–70% in 2–4 hours depending on storage conditions.

How to preserve vitamins

To preserve B vitamins in food:

• Store products in opaque packaging.
• Avoid prolonged storage under light, especially fluorescent lamps and sunlight.
• Minimize heating and oxygen exposure (do not keep open and crushed).
• Use products as soon as possible after purchase or preparation.

Thus, light — is a real destroyer of water-soluble vitamins, especially riboflavin, and with improper storage, losses can be significant within the first few hours.