Abstract
The maternal diet during pregnancy plays a critical role in shaping the long-term health of offspring. Extensive research now shows that fetal malnutrition can predispose individuals to a range of health challenges later in life. Ensuring adequate maternal nutrition is therefore essential for supporting healthy development and reducing long-term health risks for the offspring. Globally, rising living costs and changing weather patterns are increasingly limiting access to fresh produce, making inadequate intake of essential nutrients like vitamin C a growing public health concern. While scurvy, the potentially fatal disease caused by severe vitamin C deficiency, is now relatively rare in developed countries, hypovitaminosis C, or moderate vitamin C deficiency, remains widespread. This is particularly relevant for certain subpopulations, such as pregnant women, whose increased nutritional demands and a higher metabolic rate put them at greater risk of insufficiency.
While severe nutrient deficiencies like scurvy are known to compromise pregnancy outcomes, research on the potential impacts of moderate, subclinical vitamin C deficiency on pregnancy, offspring development, and disease predisposition remains limited. To determine whether poor maternal vitamin C status during pregnancy could have future health consequences for offspring, we have investigated the effects of low but non-scorbutic vitamin C intake during preconception and pregnancy in guinea pigs, a species that shares the same dietary requirements for vitamin C as humans. Dunkin Hartley guinea pigs were fed either an optimal (900mg/kg feed) or low (100mg/kg feed) vitamin C diet ad libitum during preconception. Pregnant dams were then randomised into four groups: consistently optimal, consistently low, low during early pregnancy, or low during late pregnancy. Offspring were euthanised for tissue collection within 24 hours of birth (neonates), at 28 days (juveniles), or at 4 months (adolescents).
Compared to breeding animals on the optimal diet, those on the low vitamin C diet had an increased number of unsuccessful matings, a higher incidence of fetal reabsorption, and produced significantly less offspring, altogether indicating impaired reproductive success. Low maternal vitamin C status was effectively transferred to the fetus, as evidenced by significantly decreased plasma and tissue vitamin C concentrations in pups at birth. This prenatal exposure to vitamin C depletion not only resulted in abnormal fetal and neonatal growth patterns but also had lasting consequences beyond the immediate perinatal period.
We observed distinct phenotypic differences that were dependent on both the gestational timing of vitamin C depletion and the sex of the offspring. Low maternal vitamin C intake specifically during early pregnancy triggered compensatory fetal and neonatal growth, primarily in females, and was linked to the development of a metabolic syndrome-like phenotype in both sexes by an age equivalent to early childhood. In contrast, low maternal vitamin C intake specifically during late pregnancy resulted in fetal growth restriction and reduced weight gain and fat deposition throughout the lifespan, particularly in male offspring. When maternal vitamin C intake remained consistently low throughout pregnancy, female pups exhibited slower weight gain during the early neonatal period and developed a behavioural phenotype characterised by increased risk-taking and hyperactivity by an age comparable to mid-childhood. Prenatal vitamin C depletion had profound effects on both early-life growth trajectories and long-term physiological outcomes, with sex- and timing-dependent mechanisms likely contributing to the developmental programming of disease risk.
Using immunohistochemistry and various sequencing technologies, we identified a potential underlying biological mechanism: the dysregulation of the ten-eleven translocation (TET) family of epigenetic enzymes, which are highly sensitive to vitamin C availability. As DNA demethylating enzymes, impaired TET activity resulted in DNA hypermethylation in the offspring. This builds on the concept that the epigenome plays a pivotal role in the developmental programming of health and disease.
We conclude that low vitamin C intake leads to worse reproductive and pregnancy outcomes, and that for the developing embryo and fetus, low vitamin C availability in utero disrupts the regulation of DNA methylation during early development, establishing an epigenetic legacy that alters long-term physiological outcomes in the offspring postnatally. If these effects translate to humans, this may have widespread clinical implications.