Science Update

New study demonstrates low vitamin C status in those with insulin resistance obesity and in smokers


Individuals with chronic conditions typically have increased nutrient demands than those of healthy people. These are considered conditionally essential nutrients. There is either a disruption in metabolic processes underlying inflammation oxidative stress or an inability to meet the metabolic demands with the current nutrient reserves.

In a study published five days ago in Nutrients researchers demonstrated that patients who are prediabetic have type II diabetes or smoke have lower plasma vitamin C levels.

This makes sense since insulin resistance is associated with chronic low grade inflammation; thus there will be increased vitamin C requirements to mitigate oxidative stress. There are other factors that may contribute to this as well such as vitamin C excretion in those with microalbuminuria or competition for glucose and vitamin C into the cells.

This new study included 89 patients over the age of 18 years of age who either had a normal fasting glucose prediabetes or type II diabetes. There were no significant differences in macronutrient intake of dietary vitamin C between the groups. Plasma vitamin C concentrations were significantly lower in the patients with type II diabetes and there was a much higher percent with a vitamin C deficiency in the prediabetes and diabetes groups.

As a result the researchers demonstrated that fasting glucose BMI smoking history and dietary vitamin C intake are significant independent markers of plasma vitamin C concentrations; therefore individuals that have a history of smoking prediabetes diabetes and obesity have greater vitamin C requirements. Vitamin C supplementation should be considered in these patients to prevent complications and support overall health. 

Previous research has demonstrated vitamin C doses over 200 mg per day to significantly reduce glucose concentrations.

The level of nutrient intake that maintains the best possible health is highly variable from person to person. Lifestyle choices and environmental exposures filtered through genetic predisposition are fundamental factors in the expression of disease and a successful treatment approach must include investigation into these factors.

Other conditionally essential nutrients in insulin resistance include vitamin E and inositol. A study published in 2015 in the American Journal of Clinical Nutrition demonstrated that approximately one-third of Americans who have metabolic syndrome do not absorb dietary vitamin E as effectively as healthy individuals.

Other research has shown that an inositol deficiency is common in patients with insulin resistance. There appears to be a reduced ability to process metabolize and effectively use inositol from foods which is a distinctive characteristic feature of insulin resistance. As a result the nutritional requirements of these patients may not be met by a simple change in the diet and that inositol should be viewed as a conditionally essential nutrient in these individuals.

By Michael Jurgelewicz DC DACBN DCBCN CNS

Source: Wilson R Willis J et al. Inadequate vitamin C status in prediabetes and type 2 diabetes mellitus: associations with glycaemic control obesity and smoking. Nutrients. Sept 9;9(9). Doi: 10.3390/nu9090997.