This is an update about a very important subject that is currently gaining attention in the media and among healthcare regulators – vitamin B6 supplementation and potential changes to its regulation by the Therapeutic Goods Administration (TGA).
It’s essential that all our members are up to date with the correct information regarding the risks associated with vitamin B6 toxicity and the proposed changes to access and scheduling. Please see the full update below.
NHAA MEMBER NOTICE:
Vitamin B6 – TGA Proposed Changes in Supplements – Update
Currently, vitamin B6 toxicity has been a hot topic in the media along with the potential rescheduling with the Therapeutic Goods Association (TGA). It is important that all our members are aware of the proposed TGA changes and the correct information pertaining to vitamin B6 toxicity and risk. In addition, it is important practitioners consider alternative causes for peripheral neuropathy as B6 toxicity is only one potential cause.
TGA Notice Interim Decision Amend or Not-amend Current Poisons Standard Pyridoxine/pyridoxal/pyridoxamine/vitamin B6
TGA Status on Vitamin B6
An interim decision has been made by the TGA in relation to the proposed amendment of vitamin B6 on the Poison’s Standards. The announcement proposes supplements (as listed medicines) to contain 50mg or under of pyridoxine, pyridoxal or pyridoxamine for human therapeutic use in oral preparations in the maximum recommended daily dose.
Oral preparations with more than 50mg but less than 200mg of pyridoxine, pyridoxal or pyridoxamine would become a Schedule 3 medicine, which means it can be prescribed by a pharmacist, and in dosages 200mg or more per day would become a Schedule 4 medicine for prescription by a medical practitioner.
All products that contained more than 50mg of vitamin B6 have been required to display a warning about peripheral neuropathy. Since 2022, this was lowered and now any product that has more than 10mg of vitamin B6 needs to carry a warning identifying the risk and symptoms of peripheral neuropathy associated with vitamin B6.
TGA proposed changes to vitamin B6
| Medicine type | Vitamin B6 limit | Access to finished medicine |
| Listed Medicine (supplements) | Less than or equal to 50mg | No restriction to distribution. |
| Registered medicine (Schedule 3) | (S3) More than 50mg, less than 200mg. | Restricted to Pharmacy only, prescribed by a pharmacist. Kept behind the counter in a pharmacy |
| Registered medicine (Schedule 4) | (S4) 200mg or more | Via prescription only. Dispensed by a pharmacist. |
The TGA is now seeking public opinion on the impact of these proposed decisions. As a practitioner you can submit an opinion, agreeing or opposing the decision.
Ensure your professional and personal opinion is supported with evidence, and impact on your patients and practice.
Submissions close July 27.
The below provides some additional information for your consideration.
Peripheral Neuropathy
Peripheral neuropathy (PN) is when the nerves outside of the brain and spinal cord are damaged in some way. This can cause weakness, numbness, burning, tingling, pain as well as affect digestion and urination. It is most commonly seen in the hands and feet.
Causes of Peripheral Neuropathy
- Autoimmune diseases e.g. Sjogren’s syndrome, Guillain-Barre syndrome, rheumatoid arthritis, SLE etc
- Diabetes and metabolic syndrome
- Infections e.g. Lyme disease, shingles, hepatitis B and C, leprosy, HIV
- Inherited disorders e.g. Charcot-Marie-Tooth disease
- Tumours/cancer
- Bone marrow disorders e.g. myeloma, lymphoma
- Other diseases e.g. kidney or thyroid diseases
- Alcoholism
- Exposure to poisons
- Medication e.g. neurotoxic chemotherapy
- Injury or pressure on nerves
- Vitamin/mineral deficiencies e.g. Vitamin B1, B6, B12, E and copper (magnesium and calcium affected by thyroid as well)
- Vitamin toxicity i.e. Vitamin B6
- Idiopathic peripheral neuropathy
Vitamin B6 Toxicity
A vitamin B6 toxicity is rare, however awareness of possible toxicity by medical practitioners has increased attention on this extremely rare form of peripheral neuropathy. Dietary intake of vitamin B6 foods is not enough to cause a B6 toxicity, only supplementation can lead to vitamin B6 excess. The neurological effects are caused by vitamin B6 in excess inducing cell death in a concentration-dependent manner as well as inhibition of pyridoxial-5-phosphate-dependent enzymes. This means that excess B6, can competitively inhibit the active vitamin B6 form (pyridoxal-5’-phosphate) therefore causing the symptoms of a vitamin B6 toxicity mimicking the symptoms of vitamin B6 deficiency. This means that all forms of vitamin B6 can cause a toxicity.
Typically, a vitamin B6 toxicity manifests as neurologic symptoms such as paraesthesia’s in the extremities such as hands and feet. It normally causes a sensory neuropathy such as numbness, tingling and pain in a stocking-glove distribution. This means starting in the fingers and toes and moving up the arms and legs. People may also experience ataxia and disequilibrium as well muscle weakness and bone pain.
To cause toxicity, doses of vitamin B6 need to be either excessive, 1000mg daily or 500mg per day taken for months, or lower doses over 6 to 9 months can also cause an accumulative effect. As numerous over the counter products have low doses of vitamin B6 in them, self-prescribing can lead to a vitamin B6 toxicity. This shows that any dose of vitamin B6 can cause a toxicity depending on the length of time the person has been taking it.
What to do
- Be aware of the amount of vitamin B6 in products that patients are consuming
- Ensure you ask patients of all supplements they are taking to ensure vitamin B6 intake is being monitored.
- Educate patients on a vitamin B6 toxicity and why you need to be careful of dosing
- Educate patients on the symptoms of a B6 toxicity and request blood tests if there are concerns. Remember that a blood test result may be affected by certain factors such as inflammation, recent intake of vitamin B6, alcohol intake etc
- Blood test results associated with toxicity normally need to be 10 times the upper normal limit.
- Normally, if supplementation of vitamin B6 is ceased, symptoms disappear.
NHAA opinion is to accept the proposed TGA changes to vitamin B6, along with a recommendation that naturopaths and herbalists are well positioned and educated in vitamin dosing and can therefore provide the necessary information and education to consumers and patients.
Thank you to the Industry Affairs Special Interest Group for their ongoing dedication to supporting the profession. They have prepared this report and will prepare the NHAA submission to TGA on behalf of the profession.