If you’re just starting to read and haven’t seen the previous article, I invite you to read it first. This is a continuation of a series about nutritional supplements.

Here are some facts that illustrate how nutritional deficiencies can occur and why supervised supplementation is recommended based on individual conditions:

• Caffeine consumption reduces the absorption of zinc, iron, and chromium. Additionally, it increases calcium excretion through urine and decreases B vitamins.
• Nicotine and other additives in cigarettes decrease vitamin D and vitamin C levels. They also lower concentrations of B1, B2, B5, B12, folic acid, and selenium. Calcium absorption is also reduced.
• Alcohol depletes vitamin C and certain B vitamins.
• Milk contains synthetic vitamin D, which impedes calcium absorption.
• Intensive farming has depleted soils of important minerals, such as magnesium. For example, an organic tomato contains about 200 mg of magnesium, while a “regular” tomato contains only 2 mg.
• Nitrates in vegetables convert to nitrosamines, which destroy vitamins.
• Excessive protein intake increases the need for several nutrients, especially calcium.
• Carbonated drinks/sodas deplete bones due to their phosphoric acid (E338) content.
• Antibiotics, commonly used in poultry farms and intensive livestock farming, alter gut flora and thus the absorption mechanism of many nutrients.
• Obesity and overweight themselves contribute to micronutrient deficiencies. Most individuals are deficient in vitamin D. It has been reported that deficiency prevalence can reach up to 90% in obese patients. Iron and folic acid deficiencies are also common, as well as deficiencies in vitamins B1, B12, A, E, K, zinc, copper, and calcium.

I could provide many more details. Maybe you hadn’t considered these factors in your nutrition, right?

On the other hand, there are particular situations that require special, supervised supplementation in most cases. Always following the guidance of the responsible professional.

Pregnancy and lactation: Vital stages where the intake of certain nutrients is critical. Supplementation with folate is recommended at least four weeks before conception and during the first trimester to prevent neural tube defects. Iodine and iron should be supplemented at the discretion of the doctor and based on the levels in the pregnant woman’s body.

Medications: Some medications are necessary for long periods or for life. Many long-term medications interfere with the absorption or metabolism of certain nutrients (drug-nutrient interactions). For example, some antidepressants increase the need for folate, or antacids, which hinder the absorption of B12. Metformin, the number one drug for preventing and treating type 2 diabetes, is also associated with B12 deficiency.

Special diets: For example, restrictive diets following bariatric surgery. Supplementation is even suggested before surgery due to the deficits that obese patients already have. The American Society for Metabolic and Bariatric Surgery has standardized supplementation guidelines according to the type of surgery. Another example is veganism. Especially if poorly managed, supplementation with vitamin B12 could be essential. Long-chain omega-3s might also be recommended. Other restrictive diets may lead to different deficiencies that need to be evaluated.

Diseases: Digestive issues associated with altered microbiota or irritable bowel syndrome can impair nutrient absorption, thus requiring greater intake. Malnutrition as a disease, various types of anemia. Oxidative stress caused by the imbalance between free radicals and antioxidant mechanisms can affect the integrity and functionality of lipid membranes, proteins, and nucleic acids, which has been implicated in many chronic diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases.

Sports: Physical activity with certain intensity and frequency can increase the need for some vitamins like B1, B3, or B6, or some minerals like calcium, magnesium, or iron, as well as proteins or carbohydrates. In competitive sports, the additional stress of physical and emotional tension with resulting changes in demands is also a factor.

Additionally, cooking techniques matter. Depending on how we cook food, we might be losing nutrients. For example, cooking vegetables and discarding the water results in losing most of the folate, more than 50% of B1 (thiamine), and other vitamins or minerals.

I also want to add the absorption, use, and elimination of micronutrients related to personal genetics. This can make some individuals need more of certain nutrients for optimal health.

What I’ve shared is just a part of what happens. I hope it’s enough for you to understand where many deficiencies come from. Also, to understand the individual conditions where sensible and specific supplementation designed for each condition, age, sex, and habits is necessary.

With all this, I want to make it clear that general recommendations are just that—general. As you’ve read, there are numerous factors that make it necessary to increase the intake of certain specific nutrients. This can only be done through a personalized approach, with an individual assessment.

Logically, you should first ensure that your diet is complete and balanced with well-chosen, varied, and high-quality foods; even so, supplementation may still be appropriate.