My homocysteine level was 13.5. is this high?

Yes (and no) : Most labs give a normal homocysteine level of up to 15. However, many studies have shown that once your homocysteine goes over 9, your are at increased risk for heart disease, and other problems associated wth homocysteine elevation. Homocysteine can be lowered by certain b vitamins like folate, (folic acid) b-6, b-12 and trimethylglycine. Hypothyroidism can also raise homocysteine levels.