ABC | Volume 113, Nº4, October 2019

Updated Updated Cardiovascular Prevention Guideline of the Brazilian Society Of Cardiology – 2019 Arq Bras Cardiol. 2019; 113(4):787-891 endocrine regulator of the renin-angiotensin system. Low concentrations of circulating vitamin D were associated with AH, obesity, DM, and MS; furthermore, observational studies associated the deficiency of this vitamin with the risk for CVD. 212,213 Some ecological studies suggest that vitamin D has a role in CVD, showing an increase in cardiac disease events according to the geographical latitude, that is, associated with lower exposure to solar radiation, with the concentration of vitamin D decreasing with latitude. Several prospective studies have investigated the association between plasma concentration of 25-hydroxyvitamin D and CVD, indicating an inverse relationship between the concentrations of this vitamin in the blood and the risk for CVD. 213,214 Despite this evidence, data from a systematic review conducted by Beveridge et al. 215 showed a lack of consistent benefit of vitamin D supplementation for the main markers of endothelial and vascular function. 215 A randomized, controlled, double-blind study that lasted 5.3 years tested the efficiency of daily supplementation with 2,000 IU of vitamin D3 (cholecalciferol) in 25,871 participants. 216 The primary outcomes assessed were myocardial infarction, CVA, and mortality from all CV causes, in addition to secondary outcomes of CV events. Vitamin D supplementation did not result in a lower incidence of CV events compared to placebo. The ViDA (Vitamin D Assessment) trial involved 5,108 participants in New Zealand aged 50-84 years. In the treatment group, participants received an initial dose of 200,000 IU followed a month later by 100,000 IU or placebo for an average of 3.3 years. The study found no significant reduction in CVD and mortality in the group that received vitamin D in comparison with the placebo group. 217 Although observational studies demonstrate a positive association between low concentrations of 25hydroxyvitamin D and the risk for CV events, its supplementation is not indicated to prevent CV at the moment. However, studies with an adequate design still need to prospectively investigate populations with prominent deficiencies, especially patients with CKD, and other doses of this vitamin. 218 6.5. Vitamin K The review prepared by the Cochrane Library could not assess the effectiveness of vitamin K supplementation in decreasing all-cause mortality, including CV and non-fatal outcomes (myocardial infarction, CVA, and angina), in depth because only one study met the pre-established inclusion criteria. 219 This study comprised 60 individuals aged 40-65 years investigated for three months and revealed that vitamin K2 did not change their BP and concentration of plasma lipids. The very limited results of this review highlight the lack of robust data about the efficiency of vitamin K in the primary prevention of CVD. However, the authors declared that the evidence for this assertion was minimal. A recent systematic review and meta-analysis, registered as the PROSPERO study, analyzed the results of 13 clinical trials that evaluated the effects of vitamin K supplementation on cardiometabolic risk factors in healthy individuals or a population at high risk for CVD. The study found no benefit for plasma lipids, inflammatory cytokines – such as CRP and interleukin-6 – SBP, and DBP, both in healthy individuals and among those at CV risk. 220 Therefore, the literature has no evidence to recommend vitamin K for CV prevention. 6.6. Vitamin C Vitamin C or ascorbic acid is soluble in water and a very effective antioxidant since it loses electrons easily. The free radical theory of the aging process clarifies its role in the progression of chronic diseases. 207 The Japan Collaborative Cohort Study (JACC) 221 assessed food intake in 23,119 men and 35,611 women aged 40 to 79 years without a history of CVD, and showed that the consumption of foods rich in vitamin C was inversely associated with mortality from CVD in Japanese women. Despite the beneficial effects of consuming foods rich in vitamin C shown in observational studies, RCTs do not confirm the efficiency of its supplementation in primary or secondary prevention of CVD. 222 Consequently, vitamin C supplementation is not recommended to prevent CVD. 6.7. B Vitamins and Folate Evidence of a connection between vitamin B and CVD was demonstrated by the effect of these vitamins on the reduction of homocysteine. 223,224 Homocysteine, an amino acid containing sulfur, is a metabolite produced indirectly in the demethylation of methionine. Prospective studies have shown an independent but modest association between plasma concentrations of homocysteine and the risk for CVD. 223 Some factors identified as associated with high concentrations of homocysteine are: inadequate intake of folic acid and vitamins B6 and/or B12; for this reason, the growth in plasma concentrations of homocysteine can only be one follow-up marker of an inadequate diet. Other factors that might be associated with increased homocysteine include: preexisting atherosclerotic disease, consumption of coffee and alcohol, smoking, DM, use of antiepileptic drugs or methotrexate, renal failure, rheumatoid arthritis (RA), hypothyroidism, and cystathionine beta-synthase and methylenetetrahydrofolate reductase mutations. Prospective randomized studies with a large number of CV events failed to show any benefit of folate and B complex supplementation in reducing homocysteine and preventing CVD. 208 The disagreement between the results of epidemiological studies and clinical trials might be partially due to the inclusion of different populations and the use of folic acid-fortified foods in some countries. Folic acid or B complex supplementation is not recommended to prevent CVD. 224 A recent observational study conducted in 195 countries reiterated the efficiency of consuming foods containing vitamins to prevent CV risk and mortality, associating the mortality rate of CVD attributed to diet with low intake of fruits, grains, and vegetables. 164 In conclusion, based on current evidence, a diet rich in vitamins must be encouraged; however, there is no indication that supplementation with these compounds can prevent CV events. 6.8. Omega-3 Polyunsaturated Fatty Acids of Marine Origin (Docosahexaenoic Acid and Eicosapentaenoic Acid) Omega-3 fatty acids of marine origin – docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) – produce numerous effects on different physiological and metabolic 819