Folate — 442 mcg DFE

What Folate Is

Folate takes its name from folium, the Latin for leaf, which is a fair description of where it was first found and where it is still most abundant. It is the naturally occurring form; folic acid is the synthetic form used in fortification and most supplements, and it is more stable and better absorbed.

The unit on our label, mcg DFE, stands for dietary folate equivalents, and it exists precisely because those two forms are absorbed differently. It is a way of comparing like with like.

What It Does

Carrying single carbons

Folate's entire job is to pick up single carbon atoms and deliver them where they are needed. Two of those destinations are thymidine and the purines — which is to say the actual letters DNA is written in. Without folate, a cell preparing to divide cannot finish assembling a copy of its own genome.

Why skin notices first

Any tissue that divides rapidly feels a folate shortfall before slower tissues register anything. Bone marrow is the classic example, which is why deficiency shows as anaemia. The basal layer of your epidermis is in the same category, replacing your entire skin surface roughly every month.

Working with B12

Folate is regenerated into its usable form by an enzyme that requires vitamin B12. If B12 is missing, folate becomes trapped in an unusable state no matter how much of it you consume, which is why these two nutrients are effectively one system.

When People Fall Short

Deficiency shows first in the blood, as megaloblastic anaemia: red cells that are large, immature and few, because the marrow could not finish dividing. Fatigue, breathlessness, mouth ulcers and a sore smooth tongue follow.

Risk is higher in pregnancy, where requirements rise sharply, in heavy drinkers, since alcohol interferes with folate metabolism directly, and in anyone taking methotrexate, certain anticonvulsants or sulfasalazine, all of which act on folate pathways.

Where It Occurs In Food

The Ceiling, And The Cautions

The upper limit of 1000 mcg a day applies to synthetic folic acid from supplements and fortified foods, not to folate from ordinary food, which has no established ceiling.

The masking problem is the real caution. High folate intake can correct the anaemia of a vitamin B12 deficiency while the neurological damage continues silently underneath. Nerve damage from untreated B12 deficiency can become permanent. That is the specific reason our panel carries both, and the reason anyone with tingling, numbness or unsteadiness should have B12 measured rather than supplemented blindly.

If you take methotrexate, do not add a folate supplement without your prescriber's involvement — the interaction is deliberate and part of how the drug is managed.