Vitamin K is the drummer in the nutrient supergroup, hidden away at the back while C hogs the limelight at the front of the stage and A, B, D and E smash up their instruments. But that could be set to change thanks to new research that claims taking vitamin K2 for eight weeks could improve cardiovascular performance in well-trained athletes, improving maximal cardiac output by 12%. Putting it another way, popping a pill for eight weeks improved performance by an amount that would take between six and nine months of hard training to achieve.
The study, by the University of North Texas, involved 26 male and female athletes who were randomly assigned either a vitamin K2 supplement or a placebo for eight weeks, during which time all of the subjects trained as normal. The results showed that those who took the K2 enjoyed improvements in cardiovascular performance, as well as a reduction of lactate – the potentially painful buildup of waste products caused by hard exercise – in the blood.
That Sounds Great – What’s The Catch?
There are two potential problems with the research: firstly, in scientific terms the sample of just 26 people is tiny; and secondly, the study was based around just one product, namely Nu Science Trading’s MenaquinGold Vitamin K2-7 supplement. Unsurprisingly, the company welcomed the findings.
‘This is only one study, and it was reported in an alternative therapy publication so right now it wouldn’t stand up to scientific scrutiny,’ dietician and sports nutritionist Sarah Schenker tells RISING. ‘Nor could I find any other published data of vitamin K being used in this way. It’s interesting, but more research needs to be done.’ The study’s authors recognise that. It’s far from clear whether K2 would have the same benefits for people who are only just starting to exercise. This, say the scientists, will be the subject of their next study.
How Does It Work?
This is also unclear as yet, but Schenker has a theory: ‘Vitamin K plays a role in the transport of electrons to the mitochondria, which explains why it’s been shown to play a role in preventing Parkinson’s disease.’ In simple terms, electrons help to provide energy and the mitochondria in our cells help the body to access it. Parkinson’s disease damages cells’ ability to produce energy, which in turn kills certain cells in the brain.
‘People with Parkinson’s are very different to trained athletes but the mechanism may be the same’
‘My guess is that it would work in a similar way for trained athletes – if you’re exercising hard it puts a strain on the mitochondria in the heart, so vitamin K may help transport electrons to the heart to strengthen it. People with Parkinson’s are very different to trained athletes but the mechanism may be the same,’ Schenker says.
So Supplements Could Be The Answer?
Supplements are convenient, but they also cost money, and you can usually get the nutrients you need from food. In this case, vitamin K2 can be found in meat and fermented products such as cheese. ‘There aren’t many sources but that’s not a problem because you can overdo vitamin K,’ says Schenker. ‘Too much can be harmful – so it’s not something to obsess over. If you’re training hard you should be putting the same effort into your diet and getting the nutrients you need from real food,’ she adds. ‘Don’t cut corners – you can’t expect to eat badly and then get results. And if you’re training hard to gain performance, rather than lose or manage weight, you can view food as a reward. You may be able to get away with an extra 500 calories that you wouldn’t if you were on a weight-loss plan.’
‘Don’t cut corners – you can’t expect to eat badly and then get results’
So What Nutrients Should I Target For Fitness?
The fact is there are far more essential nutrients for athletes than vitamin K. Iron is important for producing haemoglobin, the oxygen-carrying compounds in red blood cells, and endurance athletes can be prone to iron deficiency. Good sources include meat, green leafy vegetables and dried fruit or nuts. Supplements still have their place, though. ‘Vitamin D plays an important role in the immune system, which can be depleted by hard exercise,’ Schenker adds.
‘Because the primary source is sunlight this is the one thing I would recommend above all others in terms of supplementation, especially in winter. And then there’s protein, which is absolutely key for muscle repair and growth. The vitamin K research is interesting for scientists because it gives them a new lead to chase, but it’s not a bandwagon you should be jumping on just yet.’
WHAT NEXT? Nutrients are a complex subject, and while sports scientists recommend food as the first go-to here, a low-strength multivitamin is a good idea, especially if you’re training hard, because most people have ups and downs in their intake of certain food groups. But whatever you do, don’t scrimp on protein. ‘Just don’t overdo it either, because if you take on more than you need it will actually be less effective,’ says Schenker. ‘As well as taking it on after exercise you should spread it out across the day so you get a steady supply.’
Advice is for information only and should not replace medical care or recommendations. Please check with your Doctor before embarking on exercise or nutrition regimes for the first time.