number 10 / 2013 Exposition of the arms and legs to sunlight for 5’-10’ at midday in the first summer months provides about 3000 UI of Vitamin D to a person with fair complexion. People whose skin contains higher levels of melanin simply need more time in the sunlight to produce the same amount of Vitamin D as people with low melanin levels. The extraskeletal effects of Vitamin D and the need of a supplement are correlated to: 1. The changes in the body composition during the aging processes. 2. Cardiovascular risk and cerebrovascular diseases. 3. Obesity and the metabolic syndrome. 4. Diabetes. 5. Neurologic diseases such as Parkinson, Multiple Sclerosis, cognitive Decay. 6. Autoimmune diseases such as bronchial asthma, rheumatoid arthritis. 7. Infectious diseases, from tuberculosis to flu. 8. Atopic dermatitis The aging process implies a change in our body composition, with a loss of the Lean Mass (Sarcopenia) and an increase in the Fat Mass. In particular, abdominal fat is associated to the Metabolic Syndrome (according to the IDF classification it is characterised by: waistline > 90 in man > 80 in Caucasian women, AP > 130/80, glycaemia > 100mg /dl LDL>130mg/dl HDL> 40mg /dl in men > 50mg/dl in women, triglycerides > 150mg/dl). Sarcopenia – when particularly emphasized it causes unstable balance, incapacity to go up and down the stairs or carry the shopping. It increases the risk of fall and its seriousness. Osteoporosis worsens due to the reduction of the muscular tension on the skeletal structure and due to the reduction of the buffer effect of the muscle on the bone. In other words, the consequences of sarcopenia - that is, the loss of lean mass - are as follows: 1. decrease in muscular strength, power and resistance 2. decrease in bone mass 3. decrease in balance 4. decrease in the body’s amount of water 5. decrease in the basal metabolism 6. alteration of thermoregulation (intolerance and reduced response to cold) Moreover, other consequences are: • Increase in osteoporosis • Increase in the risk of fall and fracture • Increase in the adipose tissue (fat) • Increase in the cardio-vascular risk Men tend to lose by far more muscular mass than women. Some authors maintain that sarcopenia in men is the equivalent of osteoporosis in women. In women the decrease in the concentration of estrogens due to menopause causes the increase in the loss of muscular mass of about 3 kg and increases the fat mass of about 2.5 kg.
The arm measurement is an index of sarcopenia, and a correlation between this and the increase in mortality has been demonstrated. However, in obese elderly people this parameter is not enough. In order to diagnose sarcopenia, more complex instruments for body mass evaluation are required (double X-ray densitometry, bioimpedentiometry). The histological exam of muscular tissue of people with osteomalacia demonstrates an increase in the interfibrillar spaces, infiltrated with adipose tissue and fibrosis. Biopsic samples taken before and after supplementary treatment with Vitamin D and calcium have demonstrated an increase in the number and in the section area of the type IIA (or fast) muscle fibres. Moreover, it has been ascertained that the supplement of Vitamin D (1000 IU /day of ergocalciferol or Vit D /2years) was associated to an increase in percentage and in diameter of the type II muscle fibres as well as of the muscle strength. It is interesting to notice that the type II muscle fibres are the ones more involved in the prevention of fall. The levels of Vitamin D are correlated to bone mass and to an increase in the risk of femur fracture and of non-vertebral facture. These events are fought with supplements of at least 1000U/ day of Vit. D. Data show an expressive inverse correlation between vitamin D, BMI and % of fat mass. Both HOMA (index of insulin resistance) and TG (Triglycerides) / HDL (high-density lipoprotein) are correlated to the decrease of vitamin D. The levels of 25OHD are inversely correlated to the main risk factors for diabetes. Diabetic patients treated with supplements of vitamin D3 have also shown an increase in the number of T regulatory cells which, together with CCL2, act to slow down the autoimmune destruction of pancreatic cells, which characterises type 1 Diabetes. CCL2=factor which leads to the formation of TH2 cells (with anti-inflammatory and protective action towards type 1 Diabetes Mellitus). On the basis of analysed epidemiological studies, three reasons why the lack of vitamin D is a risk factor for the MS (Multiple Sclerosis) have been identified: • the frequency of MS increases at higher latitudes. • prevalence at higher altitudes is lower to the expectancy in the populations who consume more fat fish. • the risk of MS decreases in the populations who move and live at lower latitudes. Other studies show a close correlation between low levels of 25 (OH) D and risk of developing MS, and they show that the risk of developing MS significantly decreases with the increase in the levels of 25 (OH) D.
The biosynthesis of vitamin D begins in the basal layers of the skin and is caused by the sun beams, in particular by the ultraviolet radiation UVB.
Wellness & Antiaging magazine