Infertility due to poor sperm quality in men is an increasing problem. Although there may be several causes, it appears that widespread selenium deficiency is a significant factor. A lack of selenium can lead to hormonal imbalances, changes in the structure of sperm cells, and make them more vulnerable to damage caused by oxidative stress.

PCOS, also known as polycystic ovary syndrome, is one of the most common hormonal disorders and can lead to infertility, male-pattern hair growth, weight gain, impaired blood sugar regulation, and an increased risk of cardiovascular disease, type 2 diabetes, and autoimmune diseases. Evidence suggests that higher blood levels of vitamin D reduce the risk of developing PCOS. This is shown in a large population-based study published in Frontiers in Nutrition, in which the authors also examine the role of vitamin D in hormonal balance, blood sugar regulation, circulation, and fertility.

A placebo-controlled study published in Nutrition shows that magnesium supplementation can improve memory, reaction time, other cognitive skills, and heart rhythm during sleep.

Around three billion people worldwide are now deficient in vitamin B12, primarily due to plant-based dietary patterns, medication use, and aging processes. Vitamin B12 deficiency can lead to anemia, fatigue, impaired concentration, infections, gastrointestinal disorders, cardiovascular disease, reduced fertility, nerve damage, and dementia, among other conditions. Because it can take several months for a deficiency to manifest after dietary changes toward plant-based eating - and because neurological symptoms may occur without the presence of anemia - many people fail to recognize the connection. There is also evidence that vitamin B12 deficiency is associated with a higher risk of hospitalization, complications, and premature death, which calls for immediate action by health authorities. This was shown in a large Brazilian population study published in Frontiers in Nutrition.

Zinc deficiency is widespread, and a refined or plant-based diet increases the risk. The widespread zinc deficiency appears to contribute to the growing number of children who develop asthma and hay fever. In addition, zinc deficiency may be an overlooked factor that reduces the effectiveness of medical treatment, as shown in a review article published in Nutrients. According to the researchers, zinc plays a crucial role in maintaining strong mucous membranes, supporting immune function, and regulating inflammation. For this reason, zinc supplementation may represent a new, safe, and inexpensive complementary approach in the management of asthma and hay fever.

According to a large Chinese study of older adults, people who eat meat and fish have a greater chance of living to the age of 100. This surprised the researchers, who had previously assumed that a plant-based diet protects against chronic disease and premature death. They also found that older adults need considerably more protein to maintain muscle mass, as age-related muscle loss can lead to sarcopenia, reduced quality of life, and early death. One important thing to consider, is that meat contains specific amino acids needed for building muscle tissue. Meat, fish, and eggs also contain vitamin B12, iron, iodine, selenium, zinc, and omega-3 fatty acids, which are difficult or impossible to obtain in sufficient amounts from a strictly plant-based diet. For older adults and many others, the optimal approach is therefore a varied diet based on high-quality animal and plant foods.

Selenium, a key component of several selenoproteins and antioxidants, plays a crucial role in cellular energy metabolism, overall metabolism, and protection against damage caused by oxidative stress. Because of this, selenium helps delay muscle fatigue during athletic performance, reduce muscle loss, and prevent premature aging of muscles. This is highlighted in a review article published in Nutrients, where researchers summarized the latest findings on the role of different selenium compounds in muscles and optimal sports nutrition.

An increasing number of people are affected by Alzheimer’s disease, and women are significantly more at risk than men. According to a population-based study published in Alzheimer’s & Dementia, women with Alzheimer’s disease also have fewer polyunsaturated fatty acids in their brains, which appears to influence the disease progression. Since the brain contains a substantial amount of polyunsaturated fatty acids, their metabolism is particularly important for brain health. Previous studies have also shown that widespread deficiency of omega-3 fatty acids (primarily obtained through fatty fish or fish oil supplements) negatively affects brain health, increasing the risk of Alzheimer’s disease, depression, and other neurological disorders.