Vitamins for energy and heart health: omega-3 and B vitamins without the myths

Why these supplements share a section

On the pharmacy shelf, both sit under the “energy and heart” sign. In reality, omega-3 matters most if you don’t eat oily fish, and B vitamins matter if you’re at risk of low B12 or folate. Everyone else gets little from them.

Find your option: heart and energy

Pick what applies to you to see whether a supplement makes sense

What applies to you?

I rarely eat fish I'm vegan I'm over 50 Always tired

What fits

Omega-3

EPA and DHA come mainly from oily fish. Without it, a supplement is a sensible substitute.

Dose: 250–500 mg EPA+DHA a day

Omega-3 on iHerb Read the guide

Where to start

• Omega-3: how to count EPA and DHA, how the forms differ, how to check freshness and what’s known about heart benefits.
• B vitamins: what a B complex is for and why it can contain too much B6. B12 has its own guide.

The NHS recommends at least two portions of fish a week, one of them oily. If you eat that, you probably don’t need omega-3 capsules.

If you’re tired all the time, a tub of B complex is a poor first move. Rule out iron deficiency, thyroid problems and lack of sleep first: they’re the most common causes. Our guides to low ferritin and iron tablets explain the tests and doses.

Always tired? What to do, in order

A supplement is the last step, not the first. Tap a step

1Causes 2Tests 3Shortfall 4No shortfall 5Fish

Think through the usual causes

Tiredness most often comes down to low iron, low B12, a thyroid problem, lack of sleep or sleep apnoea, depression or long-term stress.

Omega-3, B vitamins and other “energy” supplements at a glance

Who each supplement is for, and what it won’t do:

Supplement	Who needs it	Dose	What not to expect
Omega-3	if you rarely eat oily fish	250–500 mg EPA+DHA	heart attack prevention in healthy people
Vitamin B12	vegans, over-50s, metformin users	as advised, or daily for vegans	energy without a deficiency
B complex	a limited diet	B6 no more than 10 mg	a lift if you already get enough
Algae omega-3	vegans	250–500 mg	–
Multivitamins	a limited or very low-calorie diet	around 100% NRV, no mega-doses	heart protection in healthy people
Spirulina	no proven need	per label	a noticeable energy lift
Taurine	no proven need	per label	extra energy in healthy people
Resveratrol	not without a clear reason	per label	anti-ageing: little human data
Alpha-lipoic acid	studied in diabetic nerve pain, with a doctor	per label	energy or weight loss
CoQ10 and ubiquinol	people on statins, if a doctor agrees	per label	extra energy in healthy people
Selenium and iodine	only with a proven low intake	stay under the upper limit	better thyroid function without a deficiency
Chromium picolinate	not for everyday use	per label	weight loss
Berberine	only with your doctor	short-term	a safe swap for diabetes medicines
Weight loss supplements	only alongside diet and activity	–	burning fat

Berberine interacts with many medicines and is not a substitute for diabetes treatment, so start with its safety section.

Common causes of constant tiredness

Check these with your GP before you buy “energy” supplements:

• iron deficiency (low ferritin shows it);
• low vitamin B12;
• thyroid problems;
• lack of sleep and sleep apnoea;
• depression and long-term stress.

Bottom line: what to choose

Rarely eat oily fish

Omega-3, 250–500 mg EPA+DHA

Triglyceride form, with food

Omega-3 on iHerb

Vegan or over 50

Vitamin B12

On its own, no extra B6

B12 on iHerb

Vegan, no fish

Algae omega-3

DHA and EPA

Algae oil on iHerb

Buttons lead to selections of the right form on iHerb. These are affiliate links; your price doesn't change.

FAQ

Can I take omega-3 and B vitamins at the same time?

Yes, they don’t interact. Take omega-3 with a meal that contains fat. Many people take B vitamins in the morning or early afternoon, as some find them slightly stimulating.

Which tests should I get if I'm always tired?

GPs usually order a full blood count, ferritin, B12, thyroid function (TSH) and glucose. The right set depends on your symptoms, so discuss it with your GP rather than testing for everything.

Do CoQ10 or chromium give you more energy?

Not in healthy people with a normal diet. CoQ10 has been studied mainly in people with heart conditions or on statins, and chromium in people with blood sugar problems. Read our guides before you buy either.