What's wrong with your B12?

“Risk comes from not knowing what you’re doing” - Warren Buffett.

Think your B12 levels are fine? Your blood test might lie to you - here’s why “upper reference limit (URL)” doesn’t always mean healthy.

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What do we know about B12?

• Supports the nervous system function

• Important for the protective myelin sheath of nerves

• Deficiency leads to cognitive impairments and anemia

Vitamin B12 plays a key role in the metabolism of fatty and amino acids and in synthesizing nucleotides (building material for DNA and RNA). Although the connection between B12 deficiency and neurological disorders is well known, the exact threshold values for adequacy remain unclear.

A recent study showed that even in healthy elderly people, "normal" B12 levels may hide brain damage.

The study aimed to determine whether B12 levels within the normal range are associated with signs of neurological damage in healthy older adults.

Low levels of active B12 led to:

• Slowed nerve conduction

• Decreased cognitive speed

• Increased areas of white matter damage on MRI

High levels of biologically inactive B12 led to:

• Increased levels of Tau protein, associated with Alzheimer's disease

Conclusion: B12 above the "norm" is not a health guarantee!

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B12 deficiency causes:

• Megaloblastic anemia

• Irreversible neurological diseases

• Increased risk of various chronic age-related diseases

• Including cognitive dysfunction

• Cardiovascular diseases

• Osteoporosis

Low B12 status in older adults is more often not a consumption deficiency, but occurs as a result of:

• Atrophic gastritis

• Use of proton pump inhibitors or other medications that suppress stomach acid

If you want to check your B12 level, you should know the following:

Measurement of total vitamin B12 in blood serum has been a standard clinical test for many years, with B12 deficiency typically defined as B12 concentrations <148 pmol/L.

However, the diagnostic sensitivity of direct assays has raised concerns, as falsely elevated results have been recorded in patients with pernicious anemia!

1. Serum B12 is not equal to active B12.
   - 80% of the total B12 in the blood is bound to the haptocorrin protein, which does not deliver the vitamin to cells.
   - Only 20% is bound to transcobalamin and actually participates in metabolism.
   - You can have a high total B12, but if it's bound to haptocorrin, cells still suffer from deficiency!

2. In people with pernicious anemia, liver and kidney diseases, B12 in the blood can be high, but it is not absorbed.

3. Hidden B12 deficiency is not detected. Even if total B12 is normal, its deficiency in tissues may already be causing neurological disorders!

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Which tests will really show B12 status?

Holotranscobalamin (Holo-TC, active B12):

• This is exactly the part of B12 that is available to cells.

• If Holo-TC < 35 pmol/L – the body is experiencing a deficiency.

Methylmalonic acid (MMA) – the best indicator of B12 deficiency!

• B12 is a cofactor of the enzyme methylmalonyl-CoA mutase.

• When B12 is deficient, the enzyme stops working, and MMA accumulates in blood and urine.

• Shows functional B12 deficiency – even if total B12 is normal!

• Specific for B12 (unlike homocysteine).

Methylmalonic acid (MMA) < 210 nmol/L – normal.

• 210-300 nmol/L – suspected deficiency.

• 300 nmol/L – confirmed deficiency.

Homocysteine (HCy)

• B12 is involved in the conversion of homocysteine to methionine.

• If B12 is insufficient – homocysteine increases, which damages blood vessels and the brain.

However, plasma homocysteine is not specific for vitamin B12 diagnosis. It is affected by other nutrients (primarily folate) and factors such as kidney function, which limits its use as a biomarker for B12 status.

A specialist can prescribe adequate measures to improve health by understanding what causes a deficiency of this important vitamin.

As doctors say, "A good diagnosis is 90% of the cure."

How to Increase Absorption of B Vitamins?

One of the keys to optimizing nutrition is the fact that many nutrients work best in combination with other vitamins. A good example of this phenomenon is non-heme iron and vitamin C.

A sufficient amount of vitamin C is required to improve the absorption of non-heme iron.

Another example of combining nutrients for optimal effect is the combination of B vitamins and omega-3 fatty acids.

B vitamins and omega-3 can actually work better when taken together.

International research published by the universities of Cape Town, Oslo, Oxford, and UAE showed that higher levels of omega-3 in blood serum can increase the effectiveness of B vitamins. 

Top foods rich in B12: clams, liver, kidneys and heart (beef, lamb, pork, chicken and turkey), oysters, mussels, octopus, mackerel, Atlantic herring, fish roe, cod liver.

Top foods rich in omega-3 (EPA, DHA): mackerel, salmon, Atlantic herring, sardines, anchovies, cod liver, fish roe.

Top foods rich in omega-3 (ALA): chia seeds, walnuts, avocado, olives.

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Warm regards,
Kos and Helen.