A group of experts has prepared a report on vitamin D supplementation for menopausal women after it was revealed that Europeans have suffered an alarming decrease in their levels of this vitamin. In their opinion, the ideal would be to maintain blood levels above 30 ng/ml. Vitamin D is essential to the immune system and processes such as calcium absorption.
"We believe that many diseases can be aggravated by a chronic deficiency of vitamin D," states Faustino R. Pérez-López, researcher at the University of Zaragoza. In particular, this is worse during the menopause as low levels of vitamin D in the blood are associated with an increased risk of osteoporosis, loss of motor coordination and bone fractures.
Vitamin D deficiency is a real problem in Europe as levels in the blood are low in 50% to 70% of the population. Pérez-López points out that "healthcare professionals should be aware that this is a common problem which affects a large part of the population in Europe, even those who live in sunny places."
Therefore, a group of experts from the European Menopause and Andropause society (EMAS), led by Pérez-López, have prepared a report about vitamin D supplementation and the health of postmenopausal women. The text has been signed by 11 experts from international institutions like the John Radcliffe Hospital in Oxford.
As Pérez-López explains, "we analysed the conditions and diseases that are associated with vitamin D deficiency and we recommended the intake of supplements in postmenopausal women."
Improvements in bone health
According to these experts, vitamin D supplements improve the mineral density of the bones and neuromuscular function and reduce the risk of fracture. Pérez-López believes that "the World Health Organisation or other relevant bodies belonging to the European Union should establish minimum requirements or recommendations on the fortification of foods with vitamin D."
There are recommendations of this type in some European countries but in others there are either no regulations or they are not strictly observed. There is not even a consensus amongst the medical community itself regarding the advantages of supplements.
Pérez-López insists however that "they are effective but its efficacy has not yet been accepted."
The researcher outlines that "it is unknown what will happen in the future but we make our recommendations from the EMAS. This is the first statement on the matter in Europe directed towards menopausal women."
As well as stimulating calcium and phosphorus absorption, the vitamin D system has numerous functions. Low vitamin D levels are linked to rickets, osteomalacia, osteoporosis and the risk of bone fracture, cardiovascular disease, diabetes, cancer, infections and degenerative diseases.
"In healthy postmenopausal women, we have seen that a good level of vitamin D is linked to good physical fitness and has an effect on body fat mass as well as muscle strength and balance," state the authors of the article published in the Maturitas journal.
A ray of sunshine
The researchers describe how "a healthy lifestyle should include exposure to the sun for 15 minutes three to four times per week when the weather permits since 90% of vitamin D is synthesized upon the skin having contact with sunlight."
Vitamin D is synthesized through sunlight exposure. Therefore, a modern lifestyle that involves little or no sun exposure and few outdoor activities causes deficiency.
Like with everything, we have to strike a balance. Pérez-López adds that "prolonged sun exposure is not recommended as it increases the risk of different types of cancer along with aging of the skin."
Substitutes to sunlight
For the experts the ideal would be to maintain blood levels above 30 ng/ml but there is no agreement as to optimum levels.
However, a large number of women are unable to obtain the required quantity of vitamin D through diet and sun exposure. As a way of making up for this deficiency, daily intake of 600 IU (international units) of vitamin D is recommended for women of up to 70 years of age and 800 IU/day for women over 70 years.
The researcher explains that "patients with risk factors associated with hypovitaminosis (obesity, pigmented skin, intestinal malabsorption syndromes and living in regions close to the North and South poles) should increase their intake to up to 4,000 IU per day." There is scientific evidence that a daily dose of 4,000 IU/day is not poisonous in healthy people.
Faustino R. Pérez-López, Marc Brincat, C. Tamer Erel, Florence Tremollieres, Marco Gambacciani, Irene Lambrinoudaki, Mette H. Moen, Karin Schenck-Gustafsson, Svetlana Vujovic, Serge Rozenberg, Margaret Rees. "Vitamin D and postmenopausal health". Maturitas, volumen 71, págs. 83-88, enero de 2012.
Vitamin D includes a series of lipophilic hormonal compounds that regulate calcium metabolism by working on the kidneys, the digestive tract, the skeleton and the parathyroid glands. Vitamin D supplements can be taken as vitamin D2 (ergocalciferol) or D3 (colecalciferol).
Vertebrates synthesize vitamin D3 in the skin through exposure to sunlight whereas a small quantity is obtained through foods such as oily fish, eggs and milk. Whether ingested or synthesized through the skin, vitamin D goes through two transformations.
The first occurs in the liver and gives rise to calcidiol. The second takes place in the kidneys and other cells and forms calcitriol - the active hormone. This hormone stimulates calcium and phosphorus absorption and regulates the transcription of different genes. It is also involved in insulin synthesis, heart contraction, it regulates the immune system, it has antimicrobial effects and controls cell proliferation and mechanisms of apoptosis.