Vitamin B12 is crucial for the nervous system and the formation of blood cells. However, the official recommendations (RI) are apparently set too low when it comes to protecting the aging brain. This is shown by an American population study, published in the Annals of Neurology, in which researchers found that older adults with "normal" but lower levels of vitamin B12 show signs of slower thinking and delayed responses to visual impressions.

Vitamin D deficiency in itself increases the risk of breast cancer. Evidence also suggests that low blood levels of vitamin D make the healing process following breast cancer surgery more painful. As a result, the use of opioid painkillers is also significantly higher, according to a study published in Regional Anesthesia & Pain Medicine. The researchers also describe the pain-relieving effects of vitamin D. Overall, there are several reasons why women with breast cancer should optimize their vitamin D status—both before surgery and throughout the rest of their lives.

Endometriosis is a common chronic disease affecting women that is associated with debilitating pain, infertility, and other symptoms. However, evidence suggests that supplementation with omega-3 fatty acids, which are found in fish oil, may relieve pain and improve quality of life in patients with the condition, according to a study published in the journal Frontiers in Nutrition. According to the researchers, the beneficial effects of fish oil are primarily due to its ability to counteract inflammation and local muscle spasms. At the same time, modern diets often contain far too little omega-3 from oily fish and too much omega-6 from seed oils, corn oil, and other processed foods. This imbalance between omega-3 and omega-6 fatty acids increases the risk of endometriosis as well as many other chronic diseases.

Every cell in the body depends on vitamin D, which regulates approximately 10 percent of our genes and plays a vital role in overall health. According to a comprehensive review published in Cancer Medicine, low blood levels of vitamin D are associated with an increased risk of bladder cancer and several other forms of cancer. The authors describe a number of biological mechanisms through which vitamin D may help protect against cancer development.

An increasing number of people are struggling with excess weight and blood sugar disorders linked to insulin resistance and prediabetes. It is estimated that 500 million people worldwide currently have type 2 diabetes, a condition associated with reduced quality of life, high blood pressure, cardiovascular disease, and premature death. Diet and lifestyle play a major role, and according to a review article published in Nutrients, vitamin K supplementation may improve blood sugar regulation through several important mechanisms.

Healthy eyes and good vision are essential throughout life. It is widely known that we need vitamin A and other antioxidants. In addition, several B vitamins (B1, B2, B3, B5, B6, B9, and B12) play different biological roles in maintaining eye health and protecting against damage caused by free radicals and oxidative stress. This is highlighted in a review article published in Clinical Ophthalmology, in which the authors also discuss eye diseases such as AMD, cataracts, glaucoma, diabetic retinopathy, and dry eyes.

Breast cancer continues to affect a growing number of women, and many experience recurrence after treatment. However, it appears that supplementing with 50 micrograms of vitamin D daily may boost the effectiveness of chemotherapy by as much as 79%, representing major potential for improving treatment outcomes. This is according to a Brazilian population study published in Nutrition and Cancer. According to the researchers, vitamin D plays a significant role in both the development and treatment of breast cancer. This is partly because vitamin D is important for immune function, the elimination of abnormal cells, and the regulation of chronic inflammation.

High blood pressure is a critical factor in cardiovascular disease, kidney disease, and premature death. As more and more people develop high blood pressure, and diet plays a crucial role, greater emphasis should be placed on prevention and treatment. A higher selenium intake also appears to reduce the risk of high blood pressure and its harmful consequences when the diet contains too many unhealthy fats. This is shown in a Chinese study published in Frontiers in Nutrition.