Speaking exclusively to Express.co.uk is pharmacist Scott McDougall, who warned that vitamin C supplementation could be making your vitamin B12 deficiency worse. “If you take vitamin C together with vitamin B12, then the former can break down the latter in your digestive tract,” said McDougall. “This reduces your vitamin B12 absorption, [which] can cause a number of physical and psychological issues.”
Furthermore, it can “lower your chances of getting heart issues, and even help protect your brain functions as you get older”.
Considering all the health benefits associated with vitamin C supplementation, it would not be surprising if you were still keen on taking the vitamin.
If this is the case, but you are currently treating a vitamin B12 deficiency, McDougall shares his top tip to keep you safe.
“Take vitamin C and vitamin B12 at least two hours apart,” he recommended.
This way, vitamin C supplementation has less chance of inhibiting vitamin B12 absorption.
There is, however, a risk of taking too much vitamin C, which can lead to digestive issues, kidney stones, and iron overload.
“Digestive issues caused by taking too much vitamin C include diarrhoea, flatulence and stomach pain,” said McDougall.
“Kidney stones can be formed when you have an excess of oxalate in your body.
“Vitamin C is excreted from your body as oxalate. This means that if you take too much vitamin C then you could be more likely to get kidney stones,” McDougall elaborated.
“Having too much iron stored in your body can lead to life-threatening issues, like heart problems, liver disease and diabetes,” he warned.
“Vitamin C boosts your body’s iron absorption levels, potential overloading it and increasing the risk of you developing a serious issue.”
The daily recommended allowance for vitamin C supplementation is 90mg.
Around 2,000mg is the “tolerable upper limit”, but certain medications mean that you should not be taking more than 1,000mg daily.
“It is possible for your vitamin C intake to reach toxic levels. It’s generally accepted that a dose of 11,900mg will kill 50 percent of people.”
Thus, before taking vitamin C supplements, it is wise to seek advice from your local pharmacist.
Pharmacist Scott McDougall (MPharm) is the co-founder and registered manager of The Independent Pharmacy.