Should I take vitamin D?

Our read is that vitamin D deficiency can lead to significant problems, particularly affecting brain function, and is linked to metabolic health and insulin resistance. Experts suggest that vitamin D plays a role in regulating the immune system, blood pressure, and bone homeostasis, and may reduce the risk of various diseases.

However, there are concerns about the safety of excessive vitamin D intake and the effectiveness of supplementation without addressing root causes or considering individual baseline levels.

A guideline for vitamin D supplementation is 1000 IU per 25 lbs of body weight, influenced by sun exposure (Bryan Johnson, Rhonda Patrick). Exposing more body surface area to the sun without sunscreen increases vitamin D production (Andrew Huberman). InsideTracker recommends foods like salmon to address vitamin D deficiency (David Sinclair).

• 01Vitamin D deficiency can lead to significant problems, particularly affecting brain function (Andrew Huberman, Rhonda Patrick).
• 02Vitamin D plays a role in regulating the immune system, blood pressure, and bone homeostasis (Andrew Huberman).
• 03Vitamin D supplementation may reduce the risk of influenza and COVID-19 infections and death (Paul Saladino).
• 04Vitamin D acts as a hormone and is involved in calcium absorption and other hormone pathways (Andrew Huberman).
• 05Vitamin D and omega-3 fatty acids are essential nutrients that most people are deficient in (Rhonda Patrick).
• 06Metabolic health and insulin resistance are linked to obesity, nutrient-poor diets, and vitamin D deficiency (Paul Saladino).
• 07Individuals with the highest levels of vitamin D have the lowest risk of cancer, heart disease, and dementia (Paul Saladino).
• 08Women supplemented with vitamin D for 9 months experienced a 25% increase in muscle strength (Rhonda Patrick).
• 09Vitamin D's long-term benefits for longevity should be considered, not just short-term outcomes like rickets (Rhonda Patrick).

Excessive vitamin D intake can be toxic, and long-term effects of excessive vitamin D3 doses are a concern (Rhonda Patrick). Hyperdosing vitamin D is unsafe and can increase falls, shifting away from its use as a primary strategy to prevent osteoporosis (Peter Attia). A daily dose of 10,000 IU of vitamin D is considered very high and is not recommended unless prescribed by a doctor (Rhonda Patrick). Relying solely on vitamin D pills to achieve benefits seen in epidemiological trials provides a false sense of security, and supplemental vitamin D has failed to show benefit in many disease models (Paul Saladino). Prescribing vitamin D or statins without addressing root causes can be harmful (Paul Saladino). Studies that do not assess baseline vitamin D status before intervention limit interpretability, and vitamin D trials should be based on target levels and measure individual response, not use fixed doses (Peter Attia, Rhonda Patrick). Biomarkers like VO2 max or strength are more indicative of longevity potential than easily manipulated biomarkers such as vitamin D levels (Peter Attia). The recommended dietary allowance for vitamin D is too low (Rhonda Patrick). Vitamin D should not be sourced from cod liver oil (Rhonda Patrick).

There is no consensus on optimal vitamin D levels, with proposed cutoffs ranging from 30 ng/mL to 75 ng/mL (Peter Attia). There is a lack of reliable RCT data comparing the health outcomes of different vitamin D blood levels (Rhonda Patrick). Lingering questions remain about whether supplementing with vitamin D is equivalent to obtaining it from sun exposure (Paul Saladino). Peter Attia aims for vitamin D levels around 50-60 ng/mL but is uncertain if aiming for 80 ng/mL would be beneficial (Peter Attia, Rhonda Patrick).