It has become a superstar among nutrition-related topics, but the recent public interest in the role of vitamin D in shaping health patterns largely makes up for decades of negligence in research into and promotion of its importance. And there is no doubt about it - the sunshine vitamin, as it is often dubbed in reference to the fact that its D3 form is generated by the skin after exposure to solar ultraviolet B light, is important.
First, it has been proven to act as a positive force in the immune system delivering stimulation which results in an increased production of the so-called natural killer cells and other defensive agents. Some researchers have postulated a link between reduced levels of vitamin D3 in wintertime and a greater likelihood of contracting a flu. Even more importantly, vitamin D is known to contribute to bone health due to its role in regulating mineral metabolism. It promotes the optimal absorption and retention of calcium and phosphorus, whose deficiency leads to serious skeletal and muscle-related diseases.
Vitamin D deficiency is particularly damaging for bones and may result in their impeded growth, deformity and brittleness, as well as the development of such conditions as osteoporosis, bone-thinning or dental problems.
Health organizations and nutrition experts have singled out sections of the population who are at particularly high risk of suffering from the consequences of being deficient in group D vitamins. They are:
people over the age of 50, mainly because their skin is less efficient in vitamin D generation and their kidneys often fail to convert it into active hormones,
- people suffering from bone ailments,
- people whose exposure to sunshine is limited, either because of natural weather conditions (e.g. in frequently overcast northern latitudes) or their inability/unwillingness to spend time outdoors,
- dark-skinned people, whose skin is not as effective in the production of vitamin D due to an increased presence of the pigment melanin,
- people who do not absorb fat well, since vitamin D requires assistance of certain fats to convert into active forms,
- people with a body mass index of over 30, whose bodies are unable to deliver sufficient amounts of group D vitamins on their own.