Life Extension Homocysteine Resist

Folate (folic acid, methylfolate)· evidence: Strong

Folate is a B vitamin needed for making red blood cells and for cell division. The strongest evidence is for women who could become pregnant: taking 400 µg of folic acid a day from before conception until 12 weeks of pregnancy lowers the risk of neural tube defects such as spina bifida. The NHS advises this for everyone trying for a baby, and some women are prescribed a higher 5 mg dose by their doctor.

Outside pregnancy planning, most people get enough folate from green vegetables, pulses and fortified cereals, and UK flour is due to be fortified with folic acid from the end of 2026. Extra folate has not been shown to help people who are not short of it.

Folic acid is the form used in the pregnancy studies. Methylfolate (5-MTHF, sold as Quatrefolic or Metafolin) is the active form and is a reasonable alternative, including for people with MTHFR gene variants, but marketing around MTHFR often overstates the problem. Most people with these variants handle folic acid well.

Typical dose: Adults need about 200 µg a day from all sources (NRV: 200 µg). Before conception to 12 weeks of pregnancy: 400 µg of folic acid a day (NHS), or 5 mg if prescribed.

Safety: The UK guidance level is 1 mg (1,000 µg) of folic acid a day from supplements unless a doctor advises more. High doses of folic acid can hide the signs of vitamin B12 deficiency, which matters most for older adults and vegans, so get B12 checked if you take high-dose folate long term. Folate can interact with some epilepsy medicines and methotrexate: check with your GP or pharmacist.

Research we looked at:
NHS. Vitamins, supplements and nutrition in pregnancy. nhs.uk/pregnancy/keeping-well/vitamins-supplements-and-nutrition
De-Regil LM et al. Effects and safety of periconceptional oral folate supplementation for preventing birth defects. Cochrane Database Syst Rev 2015;(12):CD007950.
EFSA NDA Panel. Scientific opinion on dietary reference values for folate. EFSA Journal 2014;12(11):3893.
Expert Group on Vitamins and Minerals (2003). Safe Upper Levels for Vitamins and Minerals. Food Standards Agency.

Vitamin B6· evidence: Limited

Vitamin B6 (pyridoxine, or the active form pyridoxal-5-phosphate, P-5-P) helps the body use protein and make red blood cells and some brain chemicals. Adults need only about 1.2 to 1.4 mg a day, and most people in the UK get this easily from meat, fish, wholegrains, potatoes, bananas and fortified cereals. True deficiency is uncommon.

For people who are not deficient, there is little good evidence that extra B6 does anything useful. It is often combined with magnesium or zinc in sports products; the B6 in these is mostly there to carry the label claims.

The bigger issue with B6 is safety. Long-term high doses can damage the nerves in the hands and feet, and this has been reported at doses sold freely in shops.

Typical dose: Adults need about 1.2 mg (women) to 1.4 mg (men) a day (NRV on labels: 1.4 mg). A supplement giving 1.4 to 10 mg is plenty.

Safety: The Food Standards Agency advises not taking more than 10 mg of vitamin B6 a day from supplements unless a doctor advises it. Taking more than this for a long time can cause loss of feeling in the arms and legs (peripheral neuropathy). Add up the B6 from all your supplements, including B complexes, magnesium/zinc products and multivitamins. Stop and see your GP if you notice tingling, numbness or burning in your hands or feet.

Research we looked at:
NHS. Vitamins and minerals: vitamin B6. nhs.uk/conditions/vitamins-and-minerals/vitamin-b
Expert Group on Vitamins and Minerals (2003). Safe Upper Levels for Vitamins and Minerals. Food Standards Agency.
EFSA NDA Panel. Scientific opinion on the tolerable upper intake level for vitamin B6. EFSA Journal 2023;21(5):8006.
Therapeutic Goods Administration (Australia) 2023. Safety review: vitamin B6 (pyridoxine) and peripheral neuropathy.

Vitamin B12· evidence: Strong

Vitamin B12 is needed to make red blood cells and keep the nervous system working. It is found almost only in animal foods (meat, fish, eggs, dairy) and fortified foods, so vegans need a reliable source from fortified foods or a supplement. Older adults and people taking metformin or acid-reducing medicines absorb less B12 from food.

For these groups, B12 supplements are well proven to raise B12 levels and prevent deficiency. If you already eat animal foods and absorb B12 normally, extra B12 has not been shown to boost energy.

The body absorbs only a small share of a large oral dose, which is why many products use 500 to 1,000 µg. Methylcobalamin, cyanocobalamin and other forms all work; there is no good evidence that one form is better for most people. Pernicious anaemia and other absorption problems need a diagnosis and usually injections from your GP.

Typical dose: Adults need about 1.5 µg a day (NRV on labels: 2.5 µg). Vegans: at least 10 µg a day or 2,000 µg a week (Vegan Society guidance). Supplements commonly give 10 to 1,000 µg.

Safety: No upper limit has been set because B12 has very low toxicity; the UK Expert Group on Vitamins and Minerals considered 2,000 µg a day from supplements unlikely to cause harm. Do not self-treat numbness, tingling, a sore tongue or unexplained tiredness: see your GP, as these can be signs of deficiency or pernicious anaemia that needs proper testing. Tell your doctor you take B12 before blood tests, as it raises your B12 result.

Research we looked at:
NHS. Vitamins and minerals: B vitamins and folic acid. nhs.uk/conditions/vitamins-and-minerals/vitamin-b
EFSA NDA Panel. Scientific opinion on dietary reference values for cobalamin (vitamin B12). EFSA Journal 2015;13(7):4150.
Expert Group on Vitamins and Minerals (2003). Safe Upper Levels for Vitamins and Minerals. Food Standards Agency.
NICE guideline NG239 (2024). Vitamin B12 deficiency in over 16s: diagnosis and management.

Cost per daily dose lets you compare packs of different sizes fairly.Worked out from our current prices.