Effect of Vitamin C Supplementation in Patients With Primary Hypothyroidism

Summary

Thyroid disease affects almost a quarter of a billion individuals worldwide and more than 50% of them being not aware of this condition. The commonest thyroid disease is iodine deficiency related thyroid dysfunction with nearly 2 billion people around the globe at risk with insufficient iodine intake. Autoimmune thyroid disorders are commonest cause of thyroid dysfunction in iodine sufficient parts of the world. Sub-optimally or untreated hypothyroidism can lead to cognitive decline, dyslipidemia, hypertension, infertility as well as cardiovascular and neuromuscular problems. The prevalence of hypothyroidism can vary in general population with up-to 5.3% people with overt hypothyroidism based on studies from the West, with estimated 10% of the population having subclinical hypothyroidism globally. In the gulf region however, there are no national studies that provide insight into exact prevalence of hypothyroidism, however some cross-sectional screening studies indicate frequency of hypothyroidism to be as high as 5-10%.

Levothyroxine is a synthetic hormone with structure similar to naturally occurring thyroxine, and it is used as replacement monotherapy of hypothyroidism. It is mainly absorbed via small intestine. The optimal daily levothyroxine dosage requirement is 1.6 microgram/kg body weight/day, which can normalize TSH in most patients, however many studies indicate that nearly half the patient on replacement therapy may not attain a normal TSH and require further doses, possibly due to interference or malabsorption. Multiple dose change and repeated diagnostic procedures in these patients can not only increased health costs but increased of ensuing complications secondary to sub-optimally controlled hypothyroidism. Instead of increasing levothyroxine doses and getting variable response, recent study have shown improvement in thyroid function by adding on vitamin C alongside levothyroxine dose, albeit only in a specific subset of patient having gastritis. The effect of Vitamin C on improving levothyroxine also been shown to be effective over a short period in a non-randomized, non-controlled setting. Our study aims to investigate whether addition of vitamin C to levothyroxine can improve the biochemical and clinical thyroid status in a randomized controlled setting.

Conditions

• Hypothyroidism
• Primary Hypothyroidism
• Vitamin C Deficiency

Interventions

DRUG

Vitamin C

The patient in test group will be provided vitamin C effervescent tablets to use 1 gram daily with their usual dose of Levothyroxine for 12 weeks, with thyroid function tests assessed at 6 and 12 weeks. The patients who wish to continue at the end of 12 weeks will be provided another 12 weeks supply of vitamin C effervescent tablets to use 1 gram daily with their usual dose of Levothyroxine for with thyroid function tests and clinical score assessed at the end of week 24.

DRUG

Oral Rehydration Salt Formulations

The patients in control group will have a oral rehydration effervescent tablet to take with their usual dose of Levothyroxine for 12 weeks, with thyroid function tests assessed at 6 and 12 weeks. The control group will then be provided vitamin C (intervention) effervescent tablets to use 1 gram daily with their usual dose of Levothyroxine for 12 weeks, with thyroid function tests assessed at 6 and 12 weeks to see if there is any difference on biochemical testing or clinical scores.

Sponsors & Collaborators

• Dr Adnan Agha

  lead OTHER

Principal Investigators

• Adnan Agha · United Arab Emirates University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

99 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-11-01

Primary Completion

2024-03-31

Completion

2024-06-30

Countries

• United Arab Emirates

Study Locations