Rickets was formerly a major public health problem among the US population; in Denver, almost two-thirds of 500 children had mild rickets in the late 1920s. An increase in the proportion of animal protein in the 20th-century American diet coupled with increased consumption of milk fortified with relatively small quantities of vitamin D coincided with a dramatic decline in the number of rickets cases. One study of children in a hospital in Uganda, however, showed no significant difference in vitamin D levels of malnourished children compared to non-malnourished children. Because both groups were at risk due to darker skin pigmentation, both groups had vitamin D deficiency. Nutritional status did not appear to play a role in this study. Obesity
There is an increased risk of vitamin D deficiency in people who are considered overweight or obese based on their body mass index (BMI) measurement. The relationship between these conditions is not well understood. There are different factors that could contribute to this relationship, particularly diet and sunlight exposure. Alternatively, vitamin D is fat-soluble, so excess amounts can be stored in fat tissue and used during winter, when sun exposure is limited. Sun exposure
The use of sunscreen with a sun protection factor of 8 can theoretically inhibit more than 95% of vitamin D production in the skin. In practice, however, sunscreen is applied so as to have a negligible effect on vitamin D status. The vitamin D status of those in Australia and New Zealand is unlikely to have been affected by campaigns advocating sunscreen.
It is indicated when parenteral therapy is necessary for inotropic support in the short-term treatment of patients with cardiac decompensation due to depressed contractility, which could be the result of either organic heart disease or cardiac surgical procedures. Higher doses are not useful with history of recent ischemic heart disease because it increases heart rate and thus increases myocardial oxygen demand.The drug is also commonly used in the hospital setting as a pharmacologic stress testing agent to identify coronary artery disease. Adverse effects
Primary side effects include those commonly seen for β1 active sympathomimetics, such as hypertension, angina, arrhythmia, and tachycardia. Used with caution in atrial fibrillation as it has the effect of increasing the atrioventricular (AV) conduction.The most dangerous side effect of dobutamine is increased risk of arrhythmia, including fatal arrhythmias. Overall, dobutamine tends to produce less tachycardia and peripheral vascular effects than agents such as epinephrine and isoproterenol. Pharmacology
Dobutamine is a direct-acting agent whose primary activity results from stimulation of the β1-adrenoceptors of the heart, increasing contractility and cardiac output. Since it does not act on dopamine receptors to inhibit the release of norepinephrine (another α1 agonist), dobutamine is less prone to induce hypertension than is dopamine. Dobutamine is predominantly a β1-adrenergic agonist, with weak β2 activity, and α1 selective activity, although it is used clinically in cases of cardiogenic shock for its β1 inotropic effect in increasing heart contractility and cardiac output.