ABSTRACT The effects of vitamin D on the musculoskeletal system are well established. Its deficiency causes osteomalacia, secondary hyperparathyroidism, and an increased risk for fractures and falls. However, clinical and experimental evidence points to extra-skeletal actions of vitamin D, including on immune and respiratory systems. Thus, during this COVID-19 pandemic, a possible deleterious role of vitamin D deficiency has been questioned. This paper aims to present a brief review of the literature and discuss, based on evidence, the role of vitamin D in the lung function and in the prevention of respiratory infections. Relevant articles were searched in the databases MEDLINE/PubMed and SciELO/LILACS. The mechanisms of vitamin D action in the immune system response will be discussed. Clinical data from systematic reviews and meta-analyses show benefits in the prevention of respiratory infections and improvement of pulmonary function when vitamin D-deficient patients are supplemented. At the time of writing this paper, no published data on vitamin D supplementation for patients with COVID-19 have been found. Vitamin D supplementation is recommended during this period of social isolation to avoid any deficiency, especially in the context of bone outcomes, aiming to achieve normal values of 25(OH)D. The prevention of respiratory infections and improvement of pulmonary function are additional benefits observed when vitamin D deficiency is treated. Thus far, any protective effect of vitamin D specifically against severe COVID-19 remains unclear. We also emphasize avoiding bolus or extremely high doses of vitamin D, which can increase the risk of intoxication without evidence of benefits.

O exercício físico é um estímulo muito importante para o tratamento da osteoporose. Contudo, ainda não está claro qual modalidade seria melhor para estimular o metabolismo ósseo e melhorar a função física de mulheres pós-menopausadas. Este trabalho visa resumir e atualizar os principais achados sobre os efeitos de diferentes tipos de exercícios aquáticos e de solo para a função física e metabolismo ósseo de mulheres pós-menopausadas. Exercícios moderados a intensos, executados em alta velocidade durante intervalos de tempo curtos, na água ou em solo, podem fazer parte de um programa para prevenir e tratar a osteoporose na pós-menopausa. A vibração mecânica se mostrou benéfica para a microarquitetura óssea, aumentando a densidade e a resistência ósseas, bem como melhorando a função física. Apesar de os exercícios de impacto serem  adequados para a estimulação do tecido ósseo, outras variáveis, como força muscular, tipo de contração, duração e intensidade dos exercícios, também são determinantes para induzir mudanças no metabolismo ósseo de mulheres pós-menopausadas. Além da ação sobre o osso, outras atividades que visem aumentar a força muscular e melhorar a propriocepção e o equilíbrio corporal também devem ser encorajadas para a prevenção de quedas e fraturas.

Physical exercise is an important stimulus for osteoporosis prevention and treatment. However, it is not clear yet which modality would be better to stimulate bone metabolism and enhance physical function of postmenopausal women. This review paper aims to summarize and update present knowledge on the effects of different kinds of aquatic and ground physical exercises on bone metabolism and physical function of postmenopausal women. Moderate to intense exercises, performed in a high speed during short intervals of time, in water or on the ground, can be part of a program to prevent and treat postmenopausal osteoporosis. Mechanical vibration has proven to be beneficial for bone microarchitecture, improving bone density and bone strength, as well as increasing physical function. Although impact exercises are recognized as beneficial for the stimulation of bone tissue, other variables such as muscle strength, type of muscle contraction, duration and intensity of exercises are also determinants to induce changes in bone metabolism of postmenopausal women. Not only osteoanabolic exercises should be recommended; activities aimed to develop muscle strength and body balance and improve the proprioception should be encouraged to prevent falls and fractures.