The relationship between homocysteine and B vitamins has been known for over 50 years. The authors of the European Heart Journal article also reported that current smokers had lower levels of B vitamins than nonsmokers — particularly vitamins B6, B12, and folate. Adequate B vitamins are needed to keep homocysteine at a healthy level.

Homocysteine is part of the methylation pathway, and folic acid has to be methylated to convert into 5-methyltetrahydrofolate. This reaction requires an adequate supply of folic acid, which is a B vitamin.

Defects in the methylation process can lead to serious medical problems such as cardiovascular disease, stroke, or blood clots. Other problems associated with a defect in methylation include:

• Cancer

• Defects in DNA

• Depression and mood disorders

• Inability to detoxify

• Inflammation

• Suboptimal energy production

Most labs have a reference range for homocysteine at less than 11 µmol/L. Optimal levels for both men and women are less than 9 µmol/L. Blood levels of homocysteine rise in both men and women as they age.

In addition to cardiovascular disease, a high homocysteine level is linked to kidney disease, obesity, diabetes, and thyroid illness. Medications that reduce the absorption of B vitamins can increase homocysteine. These include proton pump inhibitors (antacids). In addition, Metformin — a drug for treating diabetes — has been shown to lower levels of vitamin B12 and folic acid.

One study found that 16 weeks of Metformin treatment was associated with a 4 percent increase in homocysteine and a 7 percent decrease in folic acid, along with a 14 percent decrease in vitamin B12. And the longer Metformin is taken, the lower your vitamin B12 level can fall.

Antibiotics that negatively impact vitamin B12 and folic acid levels include azithromycin and clarithromycin, amoxicillin, fluoroquinolones, and Bactrim. Others drugs that interfere with B vitamins include diuretics, steroids, methotrexate, and nonsteroidal anti-inflammatory medications such as ibuprofen or Naproxen.

If you are on a long-term prescription medication, it’s a good idea to work with a healthcare practitioner who understands the interactions between drugs and nutrients. Proper supplementation with the appropriate nutrients can mean the difference between optimizing your health and developing a wholly different health problem due to an adverse effect from a drug.