Vitamin D is considered a safe supplement, and its consumption can benefit your health as long as you take it wisely. Hypervitaminosis could alter the delicate fluid and electrolyte balance of your body, producing an increase in blood calcium. This hypercalcemia could manifest itself in the form of confusion, apathy, or mental disorders (30).
Excess vitamin D in the blood can be as harmful as a lack of it. In fact, a higher incidence of falls and fractures has been found in people who consumed large doses of cholecalciferol (10,000 IU per day for years). This is why you should limit your consumption of vitamin D supplements to a maximum of 4,000 IU per day (29).
In addition, we recommend that you discuss with a health professional if you want to supplement for a period longer than three months. People with specificities (obesity, intestinal malabsorption, or diagnosed osteoporosis, among others) may need doses higher than 1,000-2,000 IU/day and should also consult a specialist.
Children under the age of 18, as well as pregnant and breastfeeding women, should supplement under strict clinical supervision. This also goes for anyone with a chronic disease (heart, liver, or kidney) and to individuals following the drug therapies listed in this table (31):