Her friend Emily Rose tweeted a picture of her hair stylist injecting herself and Rita with a vitamin B12 shot in the bum.

With the photo, Emily wrote: '#b12 time! I'm so ready for mine as you can see!!! @candicebirnshairstylist is not just an amazing but she gives B12 shots too! #healthiswealth'.

The shots are recommended for those who suffer from tiredness, lethargy, feeling faint and becoming breathless as a result of the reduced amount of oxygen in the blood.

A lack of vitamin B12 is a common cause for anaemia, but many celebrities use them for a pep me up.

Kelly Brook revealed earlier this year that she is a fan of the treatment.

She told a UK magazine: ‘A vitamin B12 shot in the bum does the job! They make you feel amazing - you go from a little bit groggy to 'ding!' It's probably not that sensible though…’

Victoria Beckham has also said how much she relied on the supplement during each of her pregnancies, while Chelsea Handler has made claims for the vitamin’s aphrodisiac qualities, tweeting: ‘Guess who’s getting a b12 shot for horniness?’

They join stars Madonna, Justin Timberlake, Katy Perry and Justin Bieber, who also inject the shots, according to reports.

In the UK, vitamin B12 in the injectable form is available only on prescription and should be administered under the direction of a medical professional.