Amid a surge in the availability of vitamins, minerals, and dietary supplements – now sold in supermarkets alongside traditional groceries – Spanish doctor Odile Fernández is advocating for a more discerning approach to supplementation. Her modern book, El poder de la suplementación (The Power of Supplementation), published by Planeta, argues that although supplements can be beneficial, they should be taken with careful consideration.
“Notice so many supplements available on the market that often we are misinformed. There is a lot of information, but at the same time we are misinformed due to the fact that sometimes the information overwhelms us,” Fernández explained in an interview. Her aim, she says, is “to bring some order to this vast world, where many health benefits can be obtained when supplementing intelligently.”
Fernández identifies a significant nutritional deficiency in Spain: “80% of the Spanish population has a deficiency of vitamin D.” She emphasizes its importance, stating, “We see a vitamin that is fundamental for the immune system to function properly, for my bones to be strong, but it likewise influences my mood.” This deficiency exists despite Spain being a sunny country, due to factors like spending time indoors, consistent use of sun protection, and interference from certain medications. She also points to a generally poor intake of vitamin D through diet.
“If we are going to start supplementing with something, before taking plants or taking anything else, I would start supplementing with vitamin D, especially in autumn, winter and part of spring,” she recommends.
Fernández attributes the increasing demand for supplementation to several factors, including intensive agriculture, depleted soils, the prevalence of ultra-processed foods, and chronic stress. “The apples, the tomatoes of today are not the ones from 50 years ago,” she asserts. Ultra-processed foods, she explains, lack the essential nutrients the body needs, instead providing sugar, poor-quality fats, and additives, but not vitamins or minerals.
She adds that modern lifestyles contribute to the problem. “That stress in which we live causes our body to need more minerals and vitamins to function and we are giving it increasingly worse nutrients.”
While some supplements require medical supervision – particularly plant extracts when taken alongside prescription drugs – Fernández notes that others, at appropriate doses, are generally safe for healthy individuals. She cites vitamin D, magnesium, melatonin, selenium, zinc, B vitamins, and omega-3 fatty acids as examples. However, she stresses that “the ideal is always that supplementation is supervised.” She acknowledges a systemic issue: “Supplementation is still rarely discussed in medical schools.”
Beyond supplements, Fernández highlights three core pillars of health: a Mediterranean diet, daily sun exposure, and increased physical activity. She concludes that supplementation can be a powerful tool, but should always complement – and not replace – a healthy lifestyle.
