Vaginal infections and vitamin D deficiency

Recent studies have observed a possible association between low levels of vitamin D and a greater propensity for bacterial vaginosis, even in pregnancy.

Known for decades in medicine mainly for its key role in supporting healthy skeletal development in childhood, efficient bone metabolism throughout the life course and the prevention of osteoporosis and fractures in old age, in recent years vitamin D has been shown to be actually involved in a multiplicity of processes fundamental to the health and well-being of the organism, carrying out activities that are sometimes unsuspected.

Several epidemiological studies indicate a possible association between a vitamin D deficiency and the risk of cardiovascular and metabolic diseases (in particular, hypertension and diabetes), muscle weakness, balance deficits and falls in the elderly, depression, various types of pain syndrome, alterations of the immune system (especially autoimmune diseases such as multiple sclerosis, lupus and rheumatoid arthritis) and certain forms of cancer (in particular, colorectal and breast cancer).

Recent data have shown that vitamin D may also be necessary to protect women’s intimate health and, in particular, to reduce the risk of bacterial vaginosis during pregnancy, with consequent benefits not only for the well-being of the woman, but also for the serene development of the child. But where is this vitamin found and why is it useful against vaginal infections?

Vitamin D: the forms, characteristics, sources

Vitamin D is a fat-soluble compound that accumulates in adipose tissue and fatty foods. In nature, it exists in the form of cholecalciferol (vitamin D3, the form mainly used by humans) and ergocalciferol (vitamin D2).

The first variant results from the transformation of 7-dehydro-cholesterol contained in the plasma membranes of skin cells exposed to sunlight (UvB). There are also food sources of vitamin D3: to contain significant amounts (in the fatty part and not in protein-rich meat) are mainly fish from the North Seas, such as salmon, mackerel and herring, and cod liver oil. Vitamin D2 is formed, instead, in plants by transformation of a compound similar to cholesterol (ergosterol), similarly induced by UvB radiation, and is taken through some foods, in particular green vegetables and mushrooms.

The individual requirement of vitamin D is met mainly (about 80%) through regular exposure to the sun of a sufficient surface area of the body (at least face, arms and part of the legs), for 10-15 minutes a day, both in summer and winter, without sunscreen. Hardly, however, foods that contain appreciable doses are consumed in quantities that provide a substantial contribution within the usual diet.

Given the considerable spread of conditions of vitamin D deficiency and insufficiency even in countries with good food and living standards (according to estimates, about half of the population would be affected or at risk of developing them), to promote a greater intake of this essential element through the diet, for some time, numerous foods enriched with vitamin D have been introduced on the market, often in association with calcium (of which vitamin D mediates intestinal absorption) and other micronutrients: in particular, milk, yogurt, cheese, fruit juices, breakfast cereals and special breads.

This strategy is considered useful in the general population. In the categories at greatest risk of insufficiency, it is recommended to take vitamin D supplements, in dosages and with variable frequencies depending on individual needs (established by the doctor) and the type of preparation identified.

The categories at greatest risk of vitamin D insufficiency are:

• elderly
• pregnant women
• people with muscle strength/function deficits or at risk of falls
• people with malabsorption syndromes
• obese or severely overweight subjects
• people with dark skin (African, South American, Asian origin, etc.)
• elderly people hospitalized or with reduced physical mobility
• patients on haemodialysis, with renal or hepatic impairment
• people taking medications that alter vitamin D metabolism (e.g., glucocorticoids and anticonvulsants)
• subjects who cannot expose themselves to the sun for sufficient periods for health reasons or living environment.

Vitamin D: how much to take?

Although there are no universally agreed parameters, in general the levels in the blood of vitamin D (and in particular of its metabolite 25-hydroxy-calciferol in abbreviation 25(OH)D) are considered adequate if they reach at least 30 ng / ml, insufficient if they are between 21 and 29 ng / ml and deficient if they are below 20 ng / ml.

With respect to the amount to be taken daily with the diet, general indications cannot be provided, since the factors involved in determining individual needs are countless, starting from age, the level of exposure to the sun (with the relative seasonal variations) and skin characteristics.

Even when a condition of vitamin D insufficiency is found worthy of pharmacological intervention, the type and dosage of supplementation to be undertaken must be carefully evaluated on a case-by-case basis by a doctor: this aspect is crucial because it has been shown that excess vitamin D is as toxic and harmful as deficiency.

In defining the ideal dosage of vitamin D to be taken, body weight must also be taken into account, since, with the same intake of vitamin D, people who are severely overweight or obese more often have a deficiency or insufficiency than normal weight individuals.

Vitamin D and propensity to vaginal infections

Numerous observational studies have found a link between low levels of vitamin D in the blood (measured using as a benchmark its main active metabolite, 25-hydroxy-cholecalciferol, abbreviated 25(OH)D) and incidence of bacterial vaginosis in the female population of various ages and ethnicities.

The first suspicion of a correlation between vitamin D and propensity to suffer from this vaginal infection came from the evidence that the frequency of the disorder is on average higher among women of African origin than those with fair skin and that this difference cannot be completely justified by hormonal variability, by different eating and lifestyle habits or by the lower socioeconomic level (known risk factor for vaginal infections of various kinds).

Insights in this regard have confirmed that women with darker skin, unable to produce vitamin D3 efficiently during sun exposure, more often have Caucasian levels of 25 (OH) D in the blood lower than those recommended on average to ensure good bone metabolism and, more generally, the well-being of the body.

On this basis, it was concluded that vitamin D can have a protective role against bacterial vaginosis, probably mediated by the improvement of general and local immune defenses supported by the vitamin itself, and, therefore, by the maintenance of a more stable vaginal balance and a flora richer in beneficial microorganisms (lactobacilli). The exact mechanism underlying this favorable action of vitamin D remains, however, to be determined.

Vitamin D and prevention of vaginosis in pregnancy

The association between low levels of 25(OH)D in the blood (< 20 ng/ml) and greater propensity to bacterial vaginosis has also been observed in pregnant women, particularly during the first trimester, a period in which any possible destabilization of the uterine environment can seriously harm the fetus.

The concomitant evidence that women with plasma values of 25(OH)D greater than 30-35 ng/ml are very little affected by bacterial vaginosis has led to believe that vitamin D supplementation in women with insufficient levels in early pregnancy may be an important low-cost preventive intervention to improve the course and outcome of pregnancy, ensuring greater well-being for mother and child.

Further investigations have reported that vitamin D could also have a therapeutic role against bacterial vaginosis. In particular, a study that evaluated the effects of supplementation with 2000 IU / day of vitamin D for a period of 15 weeks in women of childbearing age suffering from asymptomatic bacterial vaginosis (diagnosed with laboratory tests) and with a vitamin D deficiency, indicated that this intervention allows to eliminate bacterial vaginosis in as many as 63.5% of treated women (result obtained only by 19.2% of women included in the control, who received a placebo solution lacking vitamin D).

This evidence has important repercussions for the protection of pregnant women since the risk of preterm birth associated with bacterial vaginosis is high not only when the infection is associated with abundant foul-smelling discharge and significant intimate discomfort, but also when it is asymptomatic, and that vitamin D supplementation, calibrated according to need, It is harmless and can be beneficial to mom and baby on many fronts, including bone metabolism.

Other useful interventions to prevent vaginal infections

In addition to the possible supplementation with vitamin D, both during pregnancy and in other periods of the woman’s life, to nip in the bud, assist the treatment and prevent recurrences of bacterial vaginosis (symptomatic or not) you can resort to other safe, effective and simple to use remedies.

Among these, preparations containing prebiotics, such as glycogen and lactic acid, have proved particularly useful and well-tolerated, capable of supporting and/or restoring the balance of healthy endogenous microflora, consisting mainly of lactobacilli.

Glycogen is a polysaccharide (made up of sugars linked in chain to each other) that acts as a ready-to-use energy supply for protective lactobacilli, which are thus able to multiply more quickly and efficiently and to repopulate the vaginal mucosa compromised by vaginosis. Lactic acid, on the other hand, allows to acidify the pH, bringing it back to ideal levels to promote the growth of the same lactobacilli and to discourage that of the bacteria responsible for vaginosis (which love environments with pH closer to neutral > 4.5-5.0).

Used since the first signs of alteration of the microflora sent by the female body (generic feeling of intimate discomfort, slight itching or burning, appearance of secretions with a different smell than usual), the prebiotic gel could help reduce the risk of bacterial vaginosis. When, on the other hand, the infection is already present, the daily application of these preparations, in addition to the antibiotic therapy prescribed by the doctor, allows to obtain a more rapid improvement of the symptoms and, above all, the disappearance of the intense smell of spoiled fish taken by vaginal discharge due to the foul-smelling compounds produced by the bacteria.